diff --git a/.idea/androidTestResultsUserPreferences.xml b/.idea/androidTestResultsUserPreferences.xml
new file mode 100644
index 0000000..1ff8cba
--- /dev/null
+++ b/.idea/androidTestResultsUserPreferences.xml
@@ -0,0 +1,48 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="AndroidTestResultsUserPreferences">
+    <option name="androidTestResultsTableState">
+      <map>
+        <entry key="231168827">
+          <value>
+            <AndroidTestResultsTableState>
+              <option name="preferredColumnWidths">
+                <map>
+                  <entry key="Duration" value="90" />
+                  <entry key="Resizable_Experimental_API_34" value="120" />
+                  <entry key="Tests" value="360" />
+                </map>
+              </option>
+            </AndroidTestResultsTableState>
+          </value>
+        </entry>
+        <entry key="383667187">
+          <value>
+            <AndroidTestResultsTableState>
+              <option name="preferredColumnWidths">
+                <map>
+                  <entry key="Duration" value="90" />
+                  <entry key="Resizable_Experimental_API_34" value="120" />
+                  <entry key="Tests" value="360" />
+                </map>
+              </option>
+            </AndroidTestResultsTableState>
+          </value>
+        </entry>
+        <entry key="1145031456">
+          <value>
+            <AndroidTestResultsTableState>
+              <option name="preferredColumnWidths">
+                <map>
+                  <entry key="Duration" value="90" />
+                  <entry key="Resizable_Experimental_API_34" value="120" />
+                  <entry key="Tests" value="360" />
+                </map>
+              </option>
+            </AndroidTestResultsTableState>
+          </value>
+        </entry>
+      </map>
+    </option>
+  </component>
+</project>
\ No newline at end of file
diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index f3c1f83..01d3b93 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -1,6 +1,7 @@
 plugins {
     alias(libs.plugins.androidApplication)
     alias(libs.plugins.jetbrainsKotlinAndroid)
+
 }
 
 android {
@@ -43,6 +44,9 @@ android {
     androidResources {
         generateLocaleConfig = true
     }
+    buildFeatures{
+        viewBinding = true
+    }
 }
 
 dependencies {
@@ -68,6 +72,8 @@ dependencies {
     implementation(libs.androidx.annotation)
     implementation(libs.androidx.lifecycle.livedata.ktx)
     implementation(libs.androidx.lifecycle.viewmodel.ktx)
+    implementation(libs.androidx.datastore.rxjava3)
+    implementation(libs.androidx.datastore.preferences)
 
     testImplementation(libs.junit)
 
diff --git a/app/src/androidTest/java/uk/kagurach/android101/TestColorHelper.kt b/app/src/androidTest/java/uk/kagurach/android101/TestColorHelper.kt
new file mode 100644
index 0000000..817d96a
--- /dev/null
+++ b/app/src/androidTest/java/uk/kagurach/android101/TestColorHelper.kt
@@ -0,0 +1,31 @@
+package uk.kagurach.android101
+
+import org.junit.Assert
+import org.junit.Test
+import uk.kagurach.android101.helper.ColorHelper
+import org.junit.runner.RunWith
+
+
+class TestColorHelper {
+    val colorHelper = ColorHelper()
+
+    @Test
+    fun Test_toColorInt(){
+        Assert.assertEquals(0,colorHelper.toColorInt(0, 0, 0))
+        Assert.assertEquals(0xfffffe,colorHelper.toColorInt(255, 0xff, 254))
+    }
+
+    @Test(expected = Exception::class)
+    fun Test_error(){
+        val wtf1 = colorHelper.toColorInt(-1,256,1)
+    }
+    @Test
+    fun Test_toString(){
+        Assert.assertEquals("$000000",colorHelper.toString(0,"$"))
+        Assert.assertEquals("#ffffff",colorHelper.toString(0xffffff))
+        Assert.assertEquals("#ABCD12",colorHelper.toString(0xabcd12, upperCase = true))
+
+
+    }
+
+}
\ No newline at end of file
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 08b5324..c5955c9 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -2,7 +2,6 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
 
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
-
     <uses-permission android:name="android.permission.VIBRATE" />
 
     <application
@@ -14,6 +13,9 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/Theme.Android101">
+        <activity
+            android:name=".SettingPage"
+            android:exported="false" />
 
         <receiver
             android:name=".misc.vibrationBroadcastReceiver.vibrationBroadcastReceiver"
@@ -21,7 +23,7 @@
             android:exported="true"
             android:permission="android.permission.VIBRATE">
             <intent-filter>
-                <action android:name="uk.kagurach.android101.vibrationBroadcastReceiver"/>
+                <action android:name="uk.kagurach.android101.vibrationBroadcastReceiver" />
             </intent-filter>
         </receiver>
 
diff --git a/app/src/main/java/uk/kagurach/android101/KaBaseActivity.kt b/app/src/main/java/uk/kagurach/android101/KaBaseActivity.kt
new file mode 100644
index 0000000..aa21f22
--- /dev/null
+++ b/app/src/main/java/uk/kagurach/android101/KaBaseActivity.kt
@@ -0,0 +1,14 @@
+package uk.kagurach.android101
+
+import android.os.Bundle
+import androidx.appcompat.app.AppCompatActivity
+import kotlinx.coroutines.runBlocking
+
+
+open class KaBaseActivity : AppCompatActivity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        val storage = SettingStorage(this)
+        this.setTheme(runBlocking { storage.getDefaultTheme() })
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/uk/kagurach/android101/MainActivity.java b/app/src/main/java/uk/kagurach/android101/MainActivity.java
index 15707d5..96724b6 100644
--- a/app/src/main/java/uk/kagurach/android101/MainActivity.java
+++ b/app/src/main/java/uk/kagurach/android101/MainActivity.java
@@ -27,7 +27,7 @@ import java.util.Arrays;
 
 import uk.kagurach.android101.helper.PageHelper;
 
-public class MainActivity extends AppCompatActivity {
+public class MainActivity extends KaBaseActivity {
     PageHelper pageHelper;
 
     @Override
@@ -62,7 +62,7 @@ public class MainActivity extends AppCompatActivity {
                                 101);
             }
             textViewAppendString(tv, "Check Finished");
-            textViewAppendString(tv, "提示：常桉有惊喜");
+            textViewAppendString(tv, "提示：常按有惊喜");
         }
         textViewAppendString(tv, "*************************\nfinished");
 
@@ -73,6 +73,9 @@ public class MainActivity extends AppCompatActivity {
         button.setEnabled(true);
         button.setOnClickListener(pageHelper.pageButtonHandler);
         button.setOnLongClickListener(new LongClickHandler(this));
+
+        Button SettingPageButton = findViewById(R.id.P1OpenAppSettingsLayout);
+        SettingPageButton.setOnClickListener(new SettingPageHandler());
     }
 
     private void textViewAppendString(@NonNull TextView tv, String s) {
@@ -121,4 +124,15 @@ public class MainActivity extends AppCompatActivity {
             return false;
         }
     }
+
+    private final class SettingPageHandler implements View.OnClickListener {
+
+        @Override
+        public void onClick(View v) {
+            Intent intent = new Intent(v.getContext(),SettingPage.class);
+            intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
+            startActivity(intent);
+            finish();
+        }
+    }
 }
\ No newline at end of file
diff --git a/app/src/main/java/uk/kagurach/android101/MainActivity2.java b/app/src/main/java/uk/kagurach/android101/MainActivity2.java
index d5b4b03..ca234f9 100644
--- a/app/src/main/java/uk/kagurach/android101/MainActivity2.java
+++ b/app/src/main/java/uk/kagurach/android101/MainActivity2.java
@@ -21,10 +21,11 @@ import androidx.core.graphics.Insets;
 import androidx.core.view.ViewCompat;
 import androidx.core.view.WindowInsetsCompat;
 
+import uk.kagurach.android101.helper.ColorHelper;
 import uk.kagurach.android101.helper.PageHelper;
 import uk.kagurach.android101.helper.ToastHelper;
 
-public class MainActivity2 extends AppCompatActivity {
+public class MainActivity2 extends KaBaseActivity {
 
     PageHelper pageHelper;
 
@@ -159,9 +160,8 @@ public class MainActivity2 extends AppCompatActivity {
 
     private void updateCurrentSettingShower(){
         TextView tv = findViewById(R.id.P2SettingResult);
-        String sb = "Color = #" +
-                String.format("%6s",Integer.toString(_text_color&0xffffff, 16))
-                    .replace(" ","0") +
+        String sb = "Color = " +
+                new ColorHelper().toString(_text_color,"#",false) +
                 "; TextSize = " +
                 _text_size +
                 "." +
diff --git a/app/src/main/java/uk/kagurach/android101/Page3.java b/app/src/main/java/uk/kagurach/android101/Page3.java
index bbf10df..de9fac9 100644
--- a/app/src/main/java/uk/kagurach/android101/Page3.java
+++ b/app/src/main/java/uk/kagurach/android101/Page3.java
@@ -16,7 +16,7 @@ import androidx.core.view.WindowInsetsCompat;
 
 import uk.kagurach.android101.helper.PageHelper;
 
-public class Page3 extends AppCompatActivity {
+public class Page3 extends KaBaseActivity {
 
     PageHelper pageHelper;
 
diff --git a/app/src/main/java/uk/kagurach/android101/Page4.java b/app/src/main/java/uk/kagurach/android101/Page4.java
index 78c5152..c890ec5 100644
--- a/app/src/main/java/uk/kagurach/android101/Page4.java
+++ b/app/src/main/java/uk/kagurach/android101/Page4.java
@@ -22,7 +22,7 @@ import androidx.core.view.WindowInsetsCompat;
 import uk.kagurach.android101.helper.PageHelper;
 import uk.kagurach.android101.misc.vibrationBroadcastReceiver.vibrationBroadcastReceiver;
 
-public class Page4 extends AppCompatActivity {
+public class Page4 extends KaBaseActivity {
 
     PageHelper pageHelper;
     ActivityResultLauncher<Intent> mLauncher;
diff --git a/app/src/main/java/uk/kagurach/android101/Page5.java b/app/src/main/java/uk/kagurach/android101/Page5.java
index dfa70a7..0c20a9f 100644
--- a/app/src/main/java/uk/kagurach/android101/Page5.java
+++ b/app/src/main/java/uk/kagurach/android101/Page5.java
@@ -25,7 +25,7 @@ import uk.kagurach.android101.helper.PageHelper;
 import uk.kagurach.android101.helper.ToastHelper;
 import uk.kagurach.android101.helper.AutoCompleHelper.AnimalTypeAutoCompleteHelper;
 
-public class Page5 extends AppCompatActivity {
+public class Page5 extends KaBaseActivity {
 
     AnimalTypeAutoCompleteHelper completeHelper = null;
     final AnimalDatabaseHelper dbHelper = new AnimalDatabaseHelper(this);
diff --git a/app/src/main/java/uk/kagurach/android101/SettingPage.kt b/app/src/main/java/uk/kagurach/android101/SettingPage.kt
new file mode 100644
index 0000000..2e7a6c8
--- /dev/null
+++ b/app/src/main/java/uk/kagurach/android101/SettingPage.kt
@@ -0,0 +1,88 @@
+package uk.kagurach.android101
+
+import android.content.Context
+import android.content.Intent
+import android.os.Bundle
+import android.util.Log
+import android.view.View
+import android.widget.ImageButton
+import androidx.activity.enableEdgeToEdge
+import androidx.appcompat.app.AppCompatActivity
+import androidx.core.view.ViewCompat
+import androidx.core.view.WindowInsetsCompat
+import androidx.datastore.preferences.core.edit
+import androidx.datastore.preferences.core.intPreferencesKey
+import androidx.datastore.preferences.preferencesDataStore
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.map
+import kotlinx.coroutines.runBlocking
+import uk.kagurach.android101.databinding.ActivitySettingPageBinding
+
+import uk.kagurach.android101.helper.ColorHelper
+
+val Context.datastore by preferencesDataStore(name = "settings")
+val DefaultColor = intPreferencesKey("default_color")
+
+class SettingPage : KaBaseActivity() {
+    lateinit var binding: ActivitySettingPageBinding
+    lateinit var settingStorage: SettingStorage
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_setting_page)
+        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
+            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
+            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
+            insets
+        }
+        binding = ActivitySettingPageBinding.inflate(layoutInflater)
+        setContentView(binding.root)
+
+        settingStorage = SettingStorage(this)
+
+        binding.ThemeRed.setOnClickListener(SetColorHandler())
+        binding.ThemeBlue.setOnClickListener(SetColorHandler())
+        binding.ThemeCyan.setOnClickListener(SetColorHandler())
+        binding.ThemePink.setOnClickListener(SetColorHandler())
+        binding.ThemeGreen.setOnClickListener(SetColorHandler())
+
+        binding.SettingPageSubmit.setOnClickListener(FinishButtonHandler())
+    }
+
+
+    inner class SetColorHandler: View.OnClickListener {
+        override fun onClick(v: View?) {
+            if (v == null){
+                return
+            }
+
+            val colorTheme =  when(v.id){
+                R.id.ThemeBlue -> R.style.Theme_Blue
+                R.id.ThemeGreen -> R.style.Theme_Green
+                R.id.ThemeRed -> R.style.Theme_Red
+                R.id.ThemeCyan -> R.style.Theme_Cyan
+                R.id.ThemePink -> R.style.Theme_Pink
+                else -> {throw RuntimeException("Impossible branch met!")}
+            }
+
+            runBlocking {
+                settingStorage.setDefaultTheme(colorTheme)
+            }
+
+            val intent = Intent(v.context,this@SettingPage::class.java)
+            startActivity(intent)
+            finish()
+        }
+    }
+
+    inner class FinishButtonHandler: View.OnClickListener{
+        override fun onClick(v: View?) {
+            val intent = Intent(v!!.context,MainActivity::class.java)
+            startActivity(intent)
+            finish()
+        }
+
+    }
+
+
+}
\ No newline at end of file
diff --git a/app/src/main/java/uk/kagurach/android101/SettingStorage.kt b/app/src/main/java/uk/kagurach/android101/SettingStorage.kt
new file mode 100644
index 0000000..0ed7eb4
--- /dev/null
+++ b/app/src/main/java/uk/kagurach/android101/SettingStorage.kt
@@ -0,0 +1,28 @@
+package uk.kagurach.android101
+
+import android.content.Context
+import androidx.datastore.preferences.core.edit
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.map
+
+class SettingStorage(val context: Context) {
+
+    suspend fun getDefaultTheme(): Int {
+        return getDefaultColorFlow.first()
+    }
+    suspend fun setDefaultTheme(newValue: Int) {
+        context.datastore.edit {
+                preferences ->
+            preferences[DefaultColor] = newValue
+        }
+    }
+
+
+    private val getDefaultColorFlow: Flow<Int> =
+        context.datastore.data
+            .map {
+                    preferences ->
+                preferences[DefaultColor] ?: R.id.ThemeBlue
+            }
+}
\ No newline at end of file
diff --git a/app/src/main/java/uk/kagurach/android101/helper/ColorHelper.kt b/app/src/main/java/uk/kagurach/android101/helper/ColorHelper.kt
new file mode 100644
index 0000000..2be9a97
--- /dev/null
+++ b/app/src/main/java/uk/kagurach/android101/helper/ColorHelper.kt
@@ -0,0 +1,23 @@
+package uk.kagurach.android101.helper
+
+import android.graphics.Color
+import androidx.compose.ui.util.fastJoinToString
+
+class ColorHelper {
+    fun toColorInt(r: Int, g: Int, b: Int): Int {
+        if (r !in 0..255 || g !in 0..255 || b !in 0..255) {
+            throw Exception("RGB not in range")
+        }
+        return Color.rgb(r, g, b).and(0xffffff) // Preserve only low 48 bit
+    }
+
+    @OptIn(ExperimentalStdlibApi::class)
+    fun toString(colorInt: Int, start: String = "#", upperCase: Boolean = false): String {
+        val colorInt = colorInt.and(0xffffff) // Keep only low six digit
+        val colorString = colorInt.toHexString(
+                if (upperCase) { HexFormat.UpperCase }
+                else{ HexFormat.Default }
+        ).drop(2)
+        return "$start$colorString"
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/uk/kagurach/android101/misc/Kaculate.kt b/app/src/main/java/uk/kagurach/android101/misc/Kaculate.kt
index dac3337..85cd971 100644
--- a/app/src/main/java/uk/kagurach/android101/misc/Kaculate.kt
+++ b/app/src/main/java/uk/kagurach/android101/misc/Kaculate.kt
@@ -9,15 +9,15 @@ fun Kaculate(src: String, ctx: Context): String {
         return src
     }
 
-    val OpList = charArrayOf('+', '-', 'x', '/', '^')
+    val opList = charArrayOf('+', '-', 'x', '/', '^')
     var numStack = floatArrayOf()
     var opStack = charArrayOf()
 
     var _curnum = ""
 
     // Fix for expression starts with operator
-    val src = if (src[0] in OpList){
-        "0" + src
+    val src = if (src[0] in opList){
+        "0$src"
     }else{
         src
     }
@@ -25,7 +25,7 @@ fun Kaculate(src: String, ctx: Context): String {
     for (i in src.indices) {
         if (src[i] in '0'..'9' || src[i] == '.') {
             _curnum += src[i]
-        } else if (src[i] in OpList) {
+        } else if (src[i] in opList) {
             try {
                 numStack += _curnum.toFloat()
                 _curnum = ""
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index f925424..c585eab 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -4,25 +4,51 @@
     android:id="@+id/main"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    tools:context=".MainActivity">
+    tools:context=".MainActivity"
+    tools:viewBindingIgnore="true">
 
     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="match_parent"
-        android:orientation="vertical">
+        android:orientation="vertical"
+        android:layout_marginHorizontal="15dp"
+        android:layout_marginVertical="10dp"
+        >
 
-        <TextView
-            android:id="@+id/tv_hello"
+        <ScrollView
             android:layout_width="match_parent"
-            android:layout_height="620dp"
-            android:text="@string/hello_world"
-            android:textSize="15sp"
-            android:visibility="visible" />
+            android:layout_height="wrap_content"
+            android:minHeight="500dp"
+            >
+            <TextView
+                android:id="@+id/tv_hello"
+                android:layout_width="match_parent"
+                android:layout_height="620dp"
+                android:text="@string/hello_world"
+                android:textSize="15sp"
+                android:visibility="visible" />
+        </ScrollView>
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="80dp"
+            android:orientation="horizontal">
+
+            <Button
+                android:id="@+id/P1OpenAppSettingsLayout"
+                android:layout_width="0dp"
+                android:layout_height="match_parent"
+                android:layout_weight="1"
+                android:text="@string/settings"
+                />
+
+        </LinearLayout>
 
         <Button
             android:id="@+id/Page1NextPage"
             android:layout_width="match_parent"
             android:layout_height="0dp"
+            android:layout_marginVertical="10dp"
+            android:layout_marginHorizontal="15dp"
             android:layout_weight="1"
             android:text="@string/next_page"
             android:enabled="false"
diff --git a/app/src/main/res/layout/activity_main2.xml b/app/src/main/res/layout/activity_main2.xml
index 9ac6e9d..f9a711a 100644
--- a/app/src/main/res/layout/activity_main2.xml
+++ b/app/src/main/res/layout/activity_main2.xml
@@ -6,7 +6,9 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:windowSoftInputMode="adjustResize"
-    tools:context=".MainActivity2">
+    tools:context=".MainActivity2"
+    tools:viewBindingIgnore="true"
+    >
 
 
     <LinearLayout
diff --git a/app/src/main/res/layout/activity_page3.xml b/app/src/main/res/layout/activity_page3.xml
index b4684c3..948a2bc 100644
--- a/app/src/main/res/layout/activity_page3.xml
+++ b/app/src/main/res/layout/activity_page3.xml
@@ -4,7 +4,8 @@
     android:id="@+id/main"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    tools:context=".Page3">
+    tools:context=".Page3"
+    tools:viewBindingIgnore="true">
     <LinearLayout
         android:layout_width="match_parent"
         android:layout_height="match_parent"
diff --git a/app/src/main/res/layout/activity_page4.xml b/app/src/main/res/layout/activity_page4.xml
index 5740169..329b8a9 100644
--- a/app/src/main/res/layout/activity_page4.xml
+++ b/app/src/main/res/layout/activity_page4.xml
@@ -4,7 +4,8 @@
     android:id="@+id/main"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    tools:context=".Page4">
+    tools:context=".Page4"
+    tools:viewBindingIgnore="true">
 
     <LinearLayout
         android:layout_width="match_parent"
diff --git a/app/src/main/res/layout/activity_page5.xml b/app/src/main/res/layout/activity_page5.xml
index 0f3254b..871e441 100644
--- a/app/src/main/res/layout/activity_page5.xml
+++ b/app/src/main/res/layout/activity_page5.xml
@@ -4,7 +4,8 @@
     android:id="@+id/main"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    tools:context=".Page5">
+    tools:context=".Page5"
+    tools:viewBindingIgnore="true">
 
     <LinearLayout
         android:layout_width="match_parent"
diff --git a/app/src/main/res/layout/activity_setting_page.xml b/app/src/main/res/layout/activity_setting_page.xml
new file mode 100644
index 0000000..6ba2b08
--- /dev/null
+++ b/app/src/main/res/layout/activity_setting_page.xml
@@ -0,0 +1,104 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/main"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context=".SettingPage"
+    >
+
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        android:orientation="vertical">
+        <TextView
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="@string/settings"
+            android:textSize="45sp"
+            android:fontFamily="serif-monospace"/>
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="0dp"
+            android:layout_weight="1"
+            android:layout_marginVertical="15dp"
+            android:layout_marginHorizontal="20sp"
+            android:orientation="vertical">
+
+            <TextView
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:text="@string/set_default_theme"
+                android:textSize="30sp"/>
+            <LinearLayout
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="10dp">
+
+                <ImageButton
+                    android:id="@+id/ThemeBlue"
+                    android:layout_width="40dp"
+                    android:layout_height="40dp"
+                    android:layout_marginVertical="15dp"
+                    android:layout_marginStart="15dp"
+                    android:background="#039BE5"
+                    android:contentDescription="@string/add" />
+
+                <ImageButton
+                    android:id="@+id/ThemeGreen"
+                    android:layout_width="40dp"
+                    android:layout_height="40dp"
+                    android:layout_marginVertical="15dp"
+                    android:layout_marginStart="30dp"
+                    android:background="#43A047"
+                    android:contentDescription="@string/add" />
+
+                <ImageButton
+                    android:id="@+id/ThemeRed"
+                    android:layout_width="40dp"
+                    android:layout_height="40dp"
+                    android:layout_marginVertical="15dp"
+                    android:layout_marginStart="30dp"
+                    android:background="#E53935"
+                    android:contentDescription="@string/add" />
+
+                <ImageButton
+                    android:id="@+id/ThemeCyan"
+                    android:layout_width="40dp"
+                    android:layout_height="40dp"
+                    android:layout_marginVertical="15dp"
+                    android:layout_marginStart="30dp"
+                    android:background="#00ACC1"
+                    android:contentDescription="@string/add" />
+
+                <ImageButton
+                    android:id="@+id/ThemePink"
+                    android:layout_width="40dp"
+                    android:layout_height="40dp"
+                    android:layout_marginVertical="15dp"
+                    android:layout_marginStart="30dp"
+                    android:background="#FF80AB"
+                    android:contentDescription="@string/add" />
+
+            </LinearLayout>
+
+
+
+        </LinearLayout>
+
+        <Button
+            android:id="@+id/SettingPageSubmit"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="@string/finish"
+            android:textSize="35sp"
+            android:textAllCaps="false"
+            android:layout_marginBottom="20dp"
+            android:layout_marginHorizontal="55sp"
+            />
+
+    </LinearLayout>
+
+</androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file
diff --git a/app/src/main/res/values-night/themes.xml b/app/src/main/res/values-night/themes.xml
index 57d3d2b..199279e 100644
--- a/app/src/main/res/values-night/themes.xml
+++ b/app/src/main/res/values-night/themes.xml
@@ -2,13 +2,10 @@
     <!-- Base application theme. -->
     <style name="Theme.Android101" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
         <!-- Primary brand color. -->
-        <item name="colorPrimary">@color/purple_200</item>
-        <item name="colorPrimaryVariant">@color/purple_700</item>
+        <item name="colorPrimary">@color/tfb</item>
+        <item name="colorPrimaryVariant">@color/tfp </item>
         <item name="colorOnPrimary">@color/black</item>
         <!-- Secondary brand color. -->
-        <item name="colorSecondary">@color/teal_200</item>
-        <item name="colorSecondaryVariant">@color/teal_200</item>
-        <item name="colorOnSecondary">@color/black</item>
         <!-- Status bar color. -->
         <item name="android:statusBarColor">?attr/colorPrimaryVariant</item>
         <!-- Customize your theme here. -->
diff --git a/app/src/main/res/values-zh-rCN/strings.xml b/app/src/main/res/values-zh-rCN/strings.xml
index 13dc554..6d48bfd 100644
--- a/app/src/main/res/values-zh-rCN/strings.xml
+++ b/app/src/main/res/values-zh-rCN/strings.xml
@@ -44,4 +44,5 @@
     <string name="set_per_unit_font_size">设置每个单位的字体大小</string>
     <string name="font_size">字体\n大小</string>
     <string name="p2_default_setting">Color = #000000; TextSize = 70.sp</string>
+    <string name="set_default_theme">设置默认主题</string>
 </resources>
\ No newline at end of file
diff --git a/app/src/main/res/values/colors.xml b/app/src/main/res/values/colors.xml
index 4a795d3..03ac470 100644
--- a/app/src/main/res/values/colors.xml
+++ b/app/src/main/res/values/colors.xml
@@ -1,10 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <color name="purple_200">#FFBB86FC</color>
-    <color name="purple_500">#FF6200EE</color>
-    <color name="purple_700">#FF3700B3</color>
-    <color name="teal_200">#FF03DAC5</color>
-    <color name="teal_700">#FF018786</color>
     <color name="black">#FF000000</color>
     <color name="white">#FFFFFFFF</color>
 
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 5608c75..c4f8215 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -44,4 +44,5 @@
     <string name="set_per_unit_font_size">Set per unit font size</string>
     <string name="font_size">Font\nSize</string>
     <string name="p2_default_setting">Color = #000000; TextSize = 70.sp</string>
+    <string name="set_default_theme">Set Default Theme</string>
 </resources>
\ No newline at end of file
diff --git a/app/src/main/res/values/themes.xml b/app/src/main/res/values/themes.xml
index c1621ed..348524b 100644
--- a/app/src/main/res/values/themes.xml
+++ b/app/src/main/res/values/themes.xml
@@ -6,8 +6,8 @@
         <item name="colorPrimaryVariant">#D500F9</item>
         <item name="colorOnPrimary">@color/white</item>
         <!-- Secondary brand color. -->
-        <item name="colorSecondary">@color/teal_200</item>
-        <item name="colorSecondaryVariant">@color/teal_700</item>
+        <item name="colorSecondary">@color/black</item>
+        <item name="colorSecondaryVariant">@color/black</item>
         <item name="colorOnSecondary">@color/black</item>
         <!-- Status bar color. -->
         <item name="android:statusBarColor">#0D47A1</item>
@@ -16,5 +16,65 @@
     <style name="Theme.TODOList" parent="android:Theme.Material.Light.NoActionBar" />
     <!-- Base application theme. -->
     <style name="Base.Theme.TODOList" parent="Theme.Material3.DayNight.NoActionBar"/>
+    
+    <style name="Theme.Blue" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
+        <item name="colorPrimary">#039BE5</item>
+        <item name="colorSecondary">#1976D2</item>
+        <item name="colorSecondaryVariant">#81D4FA</item>
+        <!-- Status bar color. -->
+        <item name="android:statusBarColor">#0D47A1</item>
+        <item name="overlapAnchor">false</item>
+        <item name="android:dropDownVerticalOffset">?attr/actionBarSize</item>
+    </style>
+
+    <style name="Theme.Green" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
+        <item name="colorPrimary">#43A047</item>
+        <item name="colorSecondary">#388E3C</item>
+        <item name="colorSecondaryVariant">#A5D6A7</item>
+        <!-- Status bar color. -->
+        <item name="android:statusBarColor">#0D47A1</item>
+        <item name="overlapAnchor">false</item>
+        <item name="android:dropDownVerticalOffset">?attr/actionBarSize</item>
+    </style>
+    <style name="Theme.Red" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
+        <item name="colorPrimary">#E53935</item>
+        <item name="colorPrimaryVariant">#D500F9</item>
+        <item name="colorOnPrimary">@color/white</item>
+        <!-- Secondary brand color. -->
+        <item name="colorSecondary">@color/black</item>
+        <item name="colorSecondaryVariant">@color/black</item>
+        <item name="colorOnSecondary">@color/black</item>
+        <!-- Status bar color. -->
+        <item name="android:statusBarColor">#0D47A1</item>
+        <item name="overlapAnchor">false</item>
+        <item name="android:dropDownVerticalOffset">?attr/actionBarSize</item>
+    </style>
+    <style name="Theme.Cyan" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
+        <item name="colorPrimary">#00ACC1</item>
+        <item name="colorPrimaryVariant">#D500F9</item>
+        <item name="colorOnPrimary">@color/white</item>
+        <!-- Secondary brand color. -->
+        <item name="colorSecondary">@color/black</item>
+        <item name="colorSecondaryVariant">@color/black</item>
+        <item name="colorOnSecondary">@color/black</item>
+        <!-- Status bar color. -->
+        <item name="android:statusBarColor">#0D47A1</item>
+        <item name="overlapAnchor">false</item>
+        <item name="android:dropDownVerticalOffset">?attr/actionBarSize</item>
+    </style>
+    <style name="Theme.Pink" parent="Theme.MaterialComponents.DayNight.DarkActionBar">
+        <item name="colorPrimary">#FF80AB</item>
+        <item name="colorPrimaryVariant">#D500F9</item>
+        <item name="colorOnPrimary">@color/white</item>
+        <!-- Secondary brand color. -->
+        <item name="colorSecondary">@color/black</item>
+        <item name="colorSecondaryVariant">@color/black</item>
+        <item name="colorOnSecondary">@color/black</item>
+        <!-- Status bar color. -->
+        <item name="android:statusBarColor">#0D47A1</item>
+        <item name="overlapAnchor">false</item>
+        <item name="android:dropDownVerticalOffset">?attr/actionBarSize</item>
+    </style>
+
 
 </resources>
\ No newline at end of file
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 396c76c..2fbd6cc 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -1,5 +1,6 @@
 [versions]
 agp = "8.4.1"
+datastorePreferences = "1.1.1"
 kotlin = "1.9.0"
 coreKtx = "1.13.1"
 junit = "4.13.2"
@@ -19,9 +20,11 @@ navigationUiKtx = "2.7.7"
 annotation = "1.8.0"
 lifecycleLivedataKtx = "2.8.1"
 lifecycleViewmodelKtx = "2.8.1"
+datastoreRxjava3 = "1.1.1"
 
 [libraries]
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
+androidx-datastore-preferences = { module = "androidx.datastore:datastore-preferences", version.ref = "datastorePreferences" }
 junit = { group = "junit", name = "junit", version.ref = "junit" }
 androidx-junit = { group = "androidx.test.ext", name = "junit", version.ref = "junitVersion" }
 androidx-espresso-core = { group = "androidx.test.espresso", name = "espresso-core", version.ref = "espressoCore" }
@@ -46,6 +49,7 @@ androidx-navigation-ui-ktx = { group = "androidx.navigation", name = "navigation
 androidx-annotation = { group = "androidx.annotation", name = "annotation", version.ref = "annotation" }
 androidx-lifecycle-livedata-ktx = { group = "androidx.lifecycle", name = "lifecycle-livedata-ktx", version.ref = "lifecycleLivedataKtx" }
 androidx-lifecycle-viewmodel-ktx = { group = "androidx.lifecycle", name = "lifecycle-viewmodel-ktx", version.ref = "lifecycleViewmodelKtx" }
+androidx-datastore-rxjava3 = { group = "androidx.datastore", name = "datastore-rxjava3", version.ref = "datastoreRxjava3" }
 
 [plugins]
 androidApplication = { id = "com.android.application", version.ref = "agp" }