Change color of ripple effects and tab focus of toolbar buttons in Files

ui/file_manager/file_manager/foreground/elements/files_ripple.html

 <!-- Copyright 2015 The Chromium Authors. All rights reserved.
   -- Use of this source code is governed by a BSD-style license that can be
   -- found in the LICENSE file.
   -->
 
 <link rel="import" href="chrome://resources/polymer/v1_0/polymer/polymer.html">
 
 <dom-module id="files-ripple">
   <style>
     :host {
       align-items: center;
       display: flex;
       height: 200%;
       left: -50%;
       pointer-events: none;
       position: absolute;
       top: -50%;
       width: 200%;
     }
 
     .ripple {
-      background-color: black;
+      background-color: white;
       border-radius: 50%;
       height: 50%;
       margin: 0 auto;
       opacity: 0;
       width: 50%;
+      @apply(--files-ripple);
     }
 
     :host([pressed]) .ripple {
       opacity: 0.2;
     }
   </style>
   <template>
     <div id="ripple" class="ripple"></div>
   </template>
 </dom-module>
 
 <script src="files_ripple.js"></script>