Utilize DayNight theme when launching the app.

app/src/main/AndroidManifest.xml

@@ -151,7 +151,7 @@
                android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"/>
 
     <activity android:name=".sharing.ShareActivity"
-              android:theme="@style/TextSecure.LightNoActionBar"
+              android:theme="@style/Theme.Signal.DayNight.NoActionBar"
               android:excludeFromRecents="true"
               android:launchMode="singleTask"
               android:taskAffinity=""
@@ -184,7 +184,7 @@
     </activity>
 
     <activity android:name=".stickers.StickerPackPreviewActivity"
-              android:theme="@style/TextSecure.LightNoActionBar"
+              android:theme="@style/Theme.Signal.DayNight.NoActionBar"
               android:launchMode="singleTask"
               android:noHistory="true"
               android:windowSoftInputMode="stateHidden"
@@ -255,7 +255,7 @@
 
     <activity android:name=".groups.ui.pendingmemberinvites.PendingMemberInvitesActivity"
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"
-              android:theme="@style/TextSecure.LightNoActionBar" />
+              android:theme="@style/Theme.Signal.DayNight.NoActionBar" />
 
     <activity android:name=".groups.ui.managegroup.ManageGroupActivity"
               android:windowSoftInputMode="stateAlwaysHidden"
@@ -274,7 +274,7 @@
       <activity android:name=".PassphraseCreateActivity"
               android:label="@string/AndroidManifest__create_passphrase"
               android:windowSoftInputMode="stateUnchanged"
-              android:theme="@style/TextSecure.LightNoActionBar"
+              android:theme="@style/Theme.Signal.DayNight.NoActionBar"
               android:launchMode="singleTask"
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"/>
 
@@ -284,7 +284,7 @@
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"/>
 
     <activity android:name=".NewConversationActivity"
-              android:theme="@style/TextSecure.LightNoActionBar"
+              android:theme="@style/Theme.Signal.DayNight.NoActionBar"
               android:windowSoftInputMode="stateAlwaysVisible"
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"/>
 
@@ -294,7 +294,7 @@
           android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"/>
 
     <activity android:name=".giph.ui.GiphyActivity"
-              android:theme="@style/TextSecure.LightNoActionBar"
+              android:theme="@style/Theme.Signal.DayNight.NoActionBar"
               android:windowSoftInputMode="stateHidden"
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"/>
 
@@ -359,7 +359,7 @@
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"/>
 
     <activity android:name=".mediaoverview.MediaOverviewActivity"
-              android:theme="@style/TextSecure.LightNoActionBar"
+              android:theme="@style/Theme.Signal.DayNight.NoActionBar"
               android:windowSoftInputMode="stateHidden"
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"/>
 
@@ -411,7 +411,7 @@
     </activity>
 
     <activity android:name=".RecipientPreferenceActivity"
-              android:theme="@style/TextSecure.LightNoActionBar"
+              android:theme="@style/Theme.Signal.DayNight.NoActionBar"
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"/>
 
     <activity android:name=".mediasend.AvatarSelectionActivity"
@@ -462,44 +462,44 @@
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"/>
 
     <activity android:name=".contactshare.ContactNameEditActivity"
-              android:theme="@style/TextSecure.LightNoActionBar"
+              android:theme="@style/Theme.Signal.DayNight.NoActionBar"
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"/>
 
     <activity android:name=".contactshare.SharedContactDetailsActivity"
-              android:theme="@style/TextSecure.LightNoActionBar"
+              android:theme="@style/Theme.Signal.DayNight.NoActionBar"
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"/>
 
     <activity android:name=".ShortcutLauncherActivity"
-              android:theme="@style/TextSecure.LightNoActionBar"
+              android:theme="@style/Theme.Signal.DayNight.NoActionBar"
               android:exported="true"
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"/>
 
     <activity
             android:name=".maps.PlacePickerActivity"
             android:label="@string/PlacePickerActivity_title"
-            android:theme="@style/TextSecure.LightNoActionBar"
+            android:theme="@style/Theme.Signal.DayNight.NoActionBar"
             android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"/>
 
     <activity android:name=".MainActivity"
-              android:theme="@style/TextSecure.LightNoActionBar"
+              android:theme="@style/Theme.Signal.DayNight.NoActionBar"
               android:launchMode="singleTask"
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize" />
 
     <activity android:name=".pin.PinRestoreActivity"
-              android:theme="@style/TextSecure.LightNoActionBar"
+              android:theme="@style/Theme.Signal.DayNight.NoActionBar"
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize" />
 
     <activity android:name=".groups.ui.creategroup.CreateGroupActivity"
-              android:theme="@style/TextSecure.LightNoActionBar" />
+              android:theme="@style/Theme.Signal.DayNight.NoActionBar" />
 
     <activity android:name=".groups.ui.addtogroup.AddToGroupsActivity"
-              android:theme="@style/TextSecure.LightNoActionBar" />
+              android:theme="@style/Theme.Signal.DayNight.NoActionBar" />
 
     <activity android:name=".groups.ui.addmembers.AddMembersActivity"
-              android:theme="@style/TextSecure.LightNoActionBar" />
+              android:theme="@style/Theme.Signal.DayNight.NoActionBar" />
 
     <activity android:name=".groups.ui.creategroup.details.AddGroupDetailsActivity"
-              android:theme="@style/TextSecure.LightNoActionBar" />
+              android:theme="@style/Theme.Signal.DayNight.NoActionBar" />
 
     <service android:enabled="true" android:name="org.thoughtcrime.securesms.service.WebRtcCallService"/>
     <service android:enabled="true" android:name=".service.ApplicationMigrationService"/>

app/src/main/res/values-night/themes.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <style name="Theme.Signal.DayNight.NoActionBar" parent="TextSecure.DarkNoActionBar">
+
+    </style>
+</resources>

app/src/main/res/values/themes.xml

@@ -2,6 +2,9 @@
 
 <resources xmlns:tools="http://schemas.android.com/tools">
 
+    <style name="Theme.Signal.DayNight.NoActionBar" parent="TextSecure.LightNoActionBar">
+    </style>
+
     <style name="TextSecure.LightNoActionBar" parent="@style/TextSecure.BaseLightNoActionBar">
         <!-- leave empty to allow overriding -->
     </style>