diff --git a/app/src/main/java/org/fdroid/fdroid/AppDetails2.java b/app/src/main/java/org/fdroid/fdroid/AppDetails2.java
index 40f17cb55..7bd70df9a 100644
--- a/app/src/main/java/org/fdroid/fdroid/AppDetails2.java
+++ b/app/src/main/java/org/fdroid/fdroid/AppDetails2.java
@@ -98,7 +98,7 @@ public class AppDetails2 extends AppCompatActivity implements ShareChooserDialog
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         fdroidApp = (FDroidApp) getApplication();
-        //fdroidApp.applyTheme(this);
+        fdroidApp.applyTheme(this);
         super.onCreate(savedInstanceState);
         setContentView(R.layout.app_details2);
         Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
diff --git a/app/src/main/java/org/fdroid/fdroid/FDroidApp.java b/app/src/main/java/org/fdroid/fdroid/FDroidApp.java
index ed95dedef..fa3a435de 100644
--- a/app/src/main/java/org/fdroid/fdroid/FDroidApp.java
+++ b/app/src/main/java/org/fdroid/fdroid/FDroidApp.java
@@ -143,6 +143,24 @@ public class FDroidApp extends Application {
         }
     }
 
+    /**
+     * Force reload the {@link Activity to make theme changes take effect.}
+     * Same as {@link Languages.forceChangeLanguage}
+     *
+     * @param activity the {@code Activity} to force reload
+     */
+    public static void forceChangeTheme(Activity activity) {
+        Intent intent = activity.getIntent();
+        if (intent == null) { // when launched as LAUNCHER
+            return;
+        }
+        intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
+        activity.finish();
+        activity.overridePendingTransition(0, 0);
+        activity.startActivity(intent);
+        activity.overridePendingTransition(0, 0);
+    }
+
     public static void enableSpongyCastle() {
         Security.addProvider(SPONGYCASTLE_PROVIDER);
     }
diff --git a/app/src/main/java/org/fdroid/fdroid/privileged/views/AppSecurityPermissions.java b/app/src/main/java/org/fdroid/fdroid/privileged/views/AppSecurityPermissions.java
index 06d703b63..95fc23076 100644
--- a/app/src/main/java/org/fdroid/fdroid/privileged/views/AppSecurityPermissions.java
+++ b/app/src/main/java/org/fdroid/fdroid/privileged/views/AppSecurityPermissions.java
@@ -26,6 +26,7 @@ import android.content.pm.PackageManager;
 import android.content.pm.PackageManager.NameNotFoundException;
 import android.content.pm.PermissionGroupInfo;
 import android.content.pm.PermissionInfo;
+import android.graphics.Color;
 import android.graphics.drawable.Drawable;
 import android.os.Build;
 import android.os.Parcel;
@@ -43,6 +44,8 @@ import android.widget.LinearLayout;
 import android.widget.TextView;
 
 import org.fdroid.fdroid.R;
+import org.fdroid.fdroid.Preferences;
+import org.fdroid.fdroid.Preferences.Theme;
 
 import java.text.Collator;
 import java.util.ArrayList;
@@ -172,7 +175,9 @@ public class AppSecurityPermissions {
                 label = builder;
             }
 
+            Theme theme = Preferences.get().getTheme();
             permGrpIcon.setImageDrawable(icon);
+            permGrpIcon.setColorFilter(theme == Theme.light ? Color.BLACK : Color.WHITE);
             permNameView.setText(label);
             setOnClickListener(this);
         }
diff --git a/app/src/main/java/org/fdroid/fdroid/views/fragments/PreferencesFragment.java b/app/src/main/java/org/fdroid/fdroid/views/fragments/PreferencesFragment.java
index ed50137d5..a4e6cdd3a 100644
--- a/app/src/main/java/org/fdroid/fdroid/views/fragments/PreferencesFragment.java
+++ b/app/src/main/java/org/fdroid/fdroid/views/fragments/PreferencesFragment.java
@@ -17,6 +17,7 @@ import info.guardianproject.netcipher.NetCipher;
 import info.guardianproject.netcipher.proxy.OrbotHelper;
 import org.fdroid.fdroid.AppDetails2;
 import org.fdroid.fdroid.CleanCacheService;
+import org.fdroid.fdroid.FDroidApp;
 import org.fdroid.fdroid.Languages;
 import org.fdroid.fdroid.Preferences;
 import org.fdroid.fdroid.R;
@@ -52,6 +53,7 @@ public class PreferencesFragment extends PreferenceFragment
     private Preference updateAutoDownloadPref;
     private Preference updatePrivilegedExtensionPref;
     private long currentKeepCacheTime;
+    private FDroidApp fdroidApp;
 
     @Override
     public void onCreate(Bundle savedInstanceState) {
@@ -111,7 +113,13 @@ public class PreferencesFragment extends PreferenceFragment
 
             case Preferences.PREF_THEME:
                 entrySummary(key);
-                // TODO: Ask MainActivity to restart itself.
+                if (changing) {
+                    Activity activity = getActivity();
+                    fdroidApp = (FDroidApp) activity.getApplication();
+                    fdroidApp.reloadTheme();
+                    fdroidApp.applyTheme(activity);
+                    fdroidApp.forceChangeTheme(activity);
+                }
                 break;
 
             case Preferences.PREF_INCOMP_VER:
diff --git a/app/src/main/java/org/fdroid/fdroid/views/main/MainActivity.java b/app/src/main/java/org/fdroid/fdroid/views/main/MainActivity.java
index 1461fc582..839626207 100644
--- a/app/src/main/java/org/fdroid/fdroid/views/main/MainActivity.java
+++ b/app/src/main/java/org/fdroid/fdroid/views/main/MainActivity.java
@@ -69,6 +69,7 @@ public class MainActivity extends AppCompatActivity implements BottomNavigationB
 
     @Override
     protected void onCreate(@Nullable Bundle savedInstanceState) {
+        ((FDroidApp) getApplication()).applyTheme(this);
         super.onCreate(savedInstanceState);
 
         setContentView(R.layout.activity_main);
diff --git a/app/src/main/res/drawable/category_preview_app_card_background.xml b/app/src/main/res/drawable/category_preview_app_card_background.xml
index b2eb1a1fa..ac7b975e2 100644
--- a/app/src/main/res/drawable/category_preview_app_card_background.xml
+++ b/app/src/main/res/drawable/category_preview_app_card_background.xml
@@ -5,5 +5,5 @@
 -->
 <shape xmlns:android="http://schemas.android.com/apk/res/android">
     <corners android:radius="4dp" />
-    <solid android:color="#faf8ef" />
-</shape>
\ No newline at end of file
+    <solid android:color="?attr/categoryPreviewAppCardBackground" />
+</shape>
diff --git a/app/src/main/res/layout/app_details2.xml b/app/src/main/res/layout/app_details2.xml
index b435f3089..cb7a67242 100644
--- a/app/src/main/res/layout/app_details2.xml
+++ b/app/src/main/res/layout/app_details2.xml
@@ -6,7 +6,7 @@
     android:layout_height="match_parent"
     android:fitsSystemWindows="true"
     tools:context="org.fdroid.fdroid.AppDetails2"
-    android:background="#fcfcfc"
+    android:background="?attr/appDetailsBackground"
     android:id="@+id/rootCoordinator"
     >
 
diff --git a/app/src/main/res/layout/app_details2_header.xml b/app/src/main/res/layout/app_details2_header.xml
index c2b3ada6c..b9d242400 100755
--- a/app/src/main/res/layout/app_details2_header.xml
+++ b/app/src/main/res/layout/app_details2_header.xml
@@ -5,7 +5,7 @@
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
     android:layout_margin="@dimen/details_activity_padding"
-    app:cardBackgroundColor="#ffffff"
+    app:cardBackgroundColor="?attr/appDetailsCardBackground"
     app:cardCornerRadius="3dp"
     app:cardElevation="3dp">
 
diff --git a/app/src/main/res/layout/app_permission_item.xml b/app/src/main/res/layout/app_permission_item.xml
index ff3487840..366c1e07d 100644
--- a/app/src/main/res/layout/app_permission_item.xml
+++ b/app/src/main/res/layout/app_permission_item.xml
@@ -32,8 +32,7 @@
         android:layout_marginStart="16dp"
         android:layout_marginRight="8dp"
         android:layout_marginEnd="8dp"
-        android:scaleType="fitCenter"
-        android:tint="@android:color/black" />
+        android:scaleType="fitCenter" />
 
     <ImageView
         android:layout_width="wrap_content"
diff --git a/app/src/main/res/layout/category_item.xml b/app/src/main/res/layout/category_item.xml
index 3ad11f283..fc25031a6 100644
--- a/app/src/main/res/layout/category_item.xml
+++ b/app/src/main/res/layout/category_item.xml
@@ -14,7 +14,7 @@
         app:layout_constraintBaseline_toBaselineOf="@+id/button"
         android:textAppearance="@style/TextAppearance.AppCompat.Headline"
         android:textSize="18sp"
-        android:textColor="#4a4a4a"
+        android:textColor="?attr/categoryName"
         android:paddingLeft="18dp"
         android:paddingStart="18dp"
         android:paddingRight="18dp"
diff --git a/app/src/main/res/layout/installed_app_list_item.xml b/app/src/main/res/layout/installed_app_list_item.xml
index 0ffc031ab..e2915b766 100644
--- a/app/src/main/res/layout/installed_app_list_item.xml
+++ b/app/src/main/res/layout/installed_app_list_item.xml
@@ -32,7 +32,7 @@
         android:layout_height="wrap_content"
         tools:text="F-Droid Application manager with a long name that will wrap and then ellipsize"
         android:textSize="18sp"
-        android:textColor="#424242"
+        android:textColor="?attr/installedApps"
         android:maxLines="2"
         android:ellipsize="end"
         app:layout_constraintStart_toEndOf="@+id/icon"
@@ -51,7 +51,7 @@
         tools:text="Version 4.7.3 (recommended)"
         android:textStyle="italic"
         android:textSize="14sp"
-        android:textColor="#424242"
+        android:textColor="?attr/installedApps"
         android:maxLines="1"
         android:ellipsize="end"
         android:fontFamily="sans-serif-light"
diff --git a/app/src/main/res/layout/main_tab_swap.xml b/app/src/main/res/layout/main_tab_swap.xml
index a57eedf84..b18e5284b 100644
--- a/app/src/main/res/layout/main_tab_swap.xml
+++ b/app/src/main/res/layout/main_tab_swap.xml
@@ -5,7 +5,7 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:background="#FAFAFA">
+    android:background="?attr/mainTabSwapBackground">
 
     <TextView
         android:id="@+id/text1"
@@ -65,7 +65,7 @@
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintTop_toBottomOf="@+id/text2"
         android:layout_marginTop="36dp"
-        android:tint="#f5f5f5"
+        android:tint="?attr/mainTabSwapSplashTint"
         android:scaleType="fitXY" />
 
 </android.support.constraint.ConstraintLayout>
\ No newline at end of file
diff --git a/app/src/main/res/layout/updateable_app_list_item.xml b/app/src/main/res/layout/updateable_app_list_item.xml
index 1ee83c0e4..eba1cad05 100644
--- a/app/src/main/res/layout/updateable_app_list_item.xml
+++ b/app/src/main/res/layout/updateable_app_list_item.xml
@@ -31,7 +31,7 @@
         android:layout_height="wrap_content"
         tools:text="F-Droid Application manager with a long name that will wrap and then ellipsize"
         android:textSize="16sp"
-        android:textColor="#424242"
+        android:textColor="?attr/installedApps"
         android:lines="1"
         android:ellipsize="end"
         android:layout_marginStart="8dp"
diff --git a/app/src/main/res/layout/updateable_app_status_item.xml b/app/src/main/res/layout/updateable_app_status_item.xml
index 2b2251e43..0a1178a94 100644
--- a/app/src/main/res/layout/updateable_app_status_item.xml
+++ b/app/src/main/res/layout/updateable_app_status_item.xml
@@ -27,7 +27,7 @@
         android:layout_height="wrap_content"
         tools:text="F-Droid Application manager with a long name that will wrap and then ellipsize"
         android:textSize="16sp"
-        android:textColor="#424242"
+        android:textColor="?attr/installedApps"
         android:maxLines="2"
         android:ellipsize="end"
         app:layout_constraintStart_toEndOf="@+id/icon"
diff --git a/app/src/main/res/values/attrs.xml b/app/src/main/res/values/attrs.xml
new file mode 100644
index 000000000..0c2ed749a
--- /dev/null
+++ b/app/src/main/res/values/attrs.xml
@@ -0,0 +1,12 @@
+<?xml version='1.0' encoding='utf-8'?>
+<resources xmlns:android="http://schemas.android.com/apk/res/android">
+    <declare-styleable name="Theme">
+        <attr name="appDetailsBackground" format="color" />
+        <attr name="appDetailsCardBackground" format="color" />
+        <attr name="categoryPreviewAppCardBackground" format="color" />
+        <attr name="mainTabSwapBackground" format="color" />
+        <attr name="mainTabSwapSplashTint" format="color" />
+        <attr name="categoryName" format="color" />
+        <attr name="installedApps" format="color" />
+    </declare-styleable>
+</resources>
diff --git a/app/src/main/res/values/styles.xml b/app/src/main/res/values/styles.xml
index dcb4eaee0..99cc251e6 100644
--- a/app/src/main/res/values/styles.xml
+++ b/app/src/main/res/values/styles.xml
@@ -12,6 +12,13 @@
         <item name="android:textViewStyle">@style/TextViewStyle</item>
         <item name="actionBarTheme">@style/AppThemeLight.Toolbar</item>
         <item name="actionBarPopupTheme">@style/AppThemeLight.Toolbar</item>
+        <item name="appDetailsBackground">#0c0c0c</item>
+        <item name="appDetailsCardBackground">#000000</item>
+        <item name="categoryPreviewAppCardBackground">#000000</item>
+        <item name="mainTabSwapBackground">#0a0a0a</item>
+        <item name="mainTabSwapSplashTint">#050505</item>
+        <item name="categoryName">#ffffff</item>
+        <item name="installedApps">#ffffff</item>
     </style>
 
     <style name="AppBaseThemeLight" parent="Theme.AppCompat.Light.NoActionBar">
@@ -25,6 +32,13 @@
         <item name="android:textViewStyle">@style/TextViewStyle</item>
         <item name="actionBarTheme">@style/AppThemeLight.Toolbar</item>
         <item name="actionBarPopupTheme">@style/AppThemeLight.Toolbar</item>
+        <item name="appDetailsBackground">#fcfcfc</item>
+        <item name="appDetailsCardBackground">#ffffff</item>
+        <item name="categoryPreviewAppCardBackground">#faf8ef</item>
+        <item name="mainTabSwapBackground">#fafafa</item>
+        <item name="mainTabSwapSplashTint">#f5f5f5</item>
+        <item name="categoryName">#4a4a4a</item>
+        <item name="installedApps">#424242</item>
     </style>
 
     <style name="AppThemeDark" parent="AppBaseThemeDark">