Issue 7200 - Adjust UI colors

mobile/android/base/java/org/mozilla/gecko/tabs/TabStrip.java

 /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 package org.mozilla.gecko.tabs;
 
 import android.content.Context;
 import android.graphics.drawable.Drawable;
 import android.graphics.drawable.StateListDrawable;
@@ skipping 167 matching lines @@
     }
 
     @Override
     public void onLightweightThemeChanged() {
         final Drawable drawable = getTheme().getDrawable(this);
         if (drawable == null) {
             return;
         }
 
         final StateListDrawable stateList = new StateListDrawable();
-        // Using ABB color palette. See https://issues.adblockplus.org/ticket/3769
-        stateList.addState(PRIVATE_STATE_SET, getColorDrawable(R.color.abb_background_light_grey));
+        stateList.addState(PRIVATE_STATE_SET, getColorDrawable(R.color.text_and_tabs_tray_grey));
         stateList.addState(EMPTY_STATE_SET, drawable);
 
         setBackgroundDrawable(stateList);
     }
 
     @Override
     public void onLightweightThemeReset() {
-        // Using ABB color palette. See https://issues.adblockplus.org/ticket/3769
-        final int defaultBackgroundColor = ContextCompat.getColor(getContext(), R.color.abb_background_light_grey);
+        final int defaultBackgroundColor = ContextCompat.getColor(getContext(), R.color.text_and_tabs_tray_grey);
         setBackgroundColor(defaultBackgroundColor);
     }
 }