diff --git a/java/com/android/dialer/main/impl/OldMainActivityPeer.java b/java/com/android/dialer/main/impl/OldMainActivityPeer.java
index feb76ac..b072233 100644
--- a/java/com/android/dialer/main/impl/OldMainActivityPeer.java
+++ b/java/com/android/dialer/main/impl/OldMainActivityPeer.java
@@ -232,30 +232,12 @@
   @Override
   public void onActivityCreate(Bundle savedInstanceState) {
     LogUtil.enterBlock("OldMainActivityPeer.onActivityCreate");
-    setTheme();
     activity.setContentView(R.layout.main_activity);
     initUiListeners();
     initLayout(savedInstanceState);
     SmartDialPrefix.initializeNanpSettings(activity);
   }
 
-  /** should be called before {@link AppCompatActivity#setContentView(int)}. */
-  private void setTheme() {
-    @Theme.Type int theme = ThemeComponent.get(activity).theme().getTheme();
-    switch (theme) {
-      case Theme.DARK:
-        activity.setTheme(R.style.MainActivityTheme_Dark);
-        break;
-      case Theme.LIGHT:
-      case Theme.LIGHT_M2:
-        activity.setTheme(R.style.MainActivityTheme);
-        break;
-      case Theme.UNKNOWN:
-      default:
-        throw new IllegalArgumentException("Invalid theme.");
-    }
-  }
-
   private void initUiListeners() {
     getLastOutgoingCallListener =
         DialerExecutorComponent.get(activity)
diff --git a/java/com/android/dialer/theme/base/Theme.java b/java/com/android/dialer/theme/base/Theme.java
index 6e0d20a..47fff56 100644
--- a/java/com/android/dialer/theme/base/Theme.java
+++ b/java/com/android/dialer/theme/base/Theme.java
@@ -27,19 +27,6 @@
 /** Interface for theme. */
 public interface Theme {
 
-  /** IntDef for the different themes Dialer supports. */
-  @Retention(RetentionPolicy.SOURCE)
-  @IntDef({UNKNOWN, LIGHT, DARK, LIGHT_M2})
-  @interface Type {}
-
-  int UNKNOWN = 0;
-  int LIGHT = 1;
-  int DARK = 2;
-  int LIGHT_M2 = 3;
-
-  @Type
-  int getTheme();
-
   @StyleRes
   int getApplicationThemeRes();
 
diff --git a/java/com/android/dialer/theme/base/impl/AospThemeImpl.java b/java/com/android/dialer/theme/base/impl/AospThemeImpl.java
index c8f20c7..653392d 100644
--- a/java/com/android/dialer/theme/base/impl/AospThemeImpl.java
+++ b/java/com/android/dialer/theme/base/impl/AospThemeImpl.java
@@ -22,7 +22,6 @@
 import android.support.annotation.StyleRes;
 import android.view.ContextThemeWrapper;
 import android.view.LayoutInflater;
-import com.android.dialer.common.Assert;
 import com.android.dialer.theme.base.R;
 import com.android.dialer.theme.base.Theme;
 import javax.inject.Singleton;
@@ -47,7 +46,6 @@
   private int colorIconOnUnthemedDarkBackground = -1;
 
   public AospThemeImpl(Context context) {
-
     context = context.getApplicationContext();
     context.setTheme(getApplicationThemeRes());
     TypedArray array =
@@ -86,27 +84,9 @@
     array.recycle();
   }
 
-  /**
-   * Returns the {@link Theme} that the application is using. Activities should check this value if
-   * their custom style needs to customize further based on the application theme.
-   */
-  @Override
-  public @Type int getTheme() {
-    // TODO(a bug): add share prefs check to configure this
-    return LIGHT;
-  }
-
   @Override
   public @StyleRes int getApplicationThemeRes() {
-    switch (getTheme()) {
-      case DARK:
-        return R.style.Dialer_Dark_ThemeBase_NoActionBar;
-      case LIGHT:
-        return R.style.Dialer_ThemeBase_NoActionBar;
-      case UNKNOWN:
-      default:
-        throw Assert.createIllegalStateFailException("Theme hasn't been set yet.");
-    }
+    return R.style.Dialer_ThemeBase_NoActionBar;
   }
 
   @Override
@@ -121,55 +101,46 @@
 
   @Override
   public @ColorInt int getColorIcon() {
-    Assert.checkArgument(colorIcon != -1);
     return colorIcon;
   }
 
   @Override
   public @ColorInt int getColorIconSecondary() {
-    Assert.checkArgument(colorIconSecondary != -1);
     return colorIconSecondary;
   }
 
   @Override
   public @ColorInt int getColorPrimary() {
-    Assert.checkArgument(colorPrimary != -1);
     return colorPrimary;
   }
 
   @Override
   public int getColorPrimaryDark() {
-    Assert.checkArgument(colorPrimaryDark != -1);
     return colorPrimaryDark;
   }
 
   @Override
   public @ColorInt int getColorAccent() {
-    Assert.checkArgument(colorAccent != -1);
     return colorAccent;
   }
 
   @Override
   public @ColorInt int getTextColorSecondary() {
-    Assert.checkArgument(textColorSecondary != -1);
     return textColorSecondary;
   }
 
   @Override
   public @ColorInt int getTextColorPrimary() {
-    Assert.checkArgument(textColorPrimary != -1);
     return textColorPrimary;
   }
 
   @Override
   public @ColorInt int getColorTextOnUnthemedDarkBackground() {
-    Assert.checkArgument(colorTextOnUnthemedDarkBackground != -1);
     return colorTextOnUnthemedDarkBackground;
   }
 
   @Override
   public @ColorInt int getColorIconOnUnthemedDarkBackground() {
-    Assert.checkArgument(colorIconOnUnthemedDarkBackground != -1);
     return colorIconOnUnthemedDarkBackground;
   }
 }
diff --git a/java/com/android/dialer/theme/base/res/values-night-v31/styles.xml b/java/com/android/dialer/theme/base/res/values-night-v31/styles.xml
index 8130c88..1a0579b 100644
--- a/java/com/android/dialer/theme/base/res/values-night-v31/styles.xml
+++ b/java/com/android/dialer/theme/base/res/values-night-v31/styles.xml
@@ -34,7 +34,7 @@
     <item name="android:colorAccent">?android:attr/colorPrimary</item>
   </style>
   
-    <style name="Dialer.ThemeBase.ActionBar">
+    <style name="Dialer.ThemeBase.ActionBar" parent="Dialer.ThemeBase">
     <item name="android:windowLightStatusBar">false</item>
     <item name="android:windowLightNavigationBar">false</item>
     <item name="android:statusBarColor">@android:color/transparent</item>
@@ -51,7 +51,7 @@
     <item name="listChoiceBackgroundIndicator">@drawable/abc_list_selector_holo_dark</item>
   </style>
 
-  <style name="Dialer.ThemeBase.NoActionBar">
+  <style name="Dialer.ThemeBase.NoActionBar" parent="Dialer.ThemeBase">
     <item name="android:windowLightStatusBar">false</item>
     <item name="android:windowLightNavigationBar">false</item>
     <item name="android:statusBarColor">@android:color/transparent</item>
diff --git a/java/com/android/dialer/theme/base/res/values-v31/styles.xml b/java/com/android/dialer/theme/base/res/values-v31/styles.xml
index b811508..82df4c8 100644
--- a/java/com/android/dialer/theme/base/res/values-v31/styles.xml
+++ b/java/com/android/dialer/theme/base/res/values-v31/styles.xml
@@ -34,7 +34,7 @@
     <item name="android:colorAccent">?android:attr/colorPrimary</item>
   </style>
   
-    <style name="Dialer.ThemeBase.ActionBar">
+  <style name="Dialer.ThemeBase.ActionBar" parent="Dialer.ThemeBase">
     <item name="android:windowLightStatusBar">true</item>
     <item name="android:windowLightNavigationBar">true</item>
     <item name="android:statusBarColor">@android:color/transparent</item>
@@ -50,7 +50,7 @@
     <item name="listChoiceBackgroundIndicator">@drawable/abc_list_selector_holo_dark</item>
   </style>
   
-  <style name="Dialer.ThemeBase.NoActionBar">
+  <style name="Dialer.ThemeBase.NoActionBar" parent="Dialer.ThemeBase">
     <item name="android:windowLightStatusBar">true</item>
     <item name="android:windowLightNavigationBar">true</item>
     <item name="android:statusBarColor">@android:color/transparent</item>