[MD settings] settings icon color per spec

chrome/browser/resources/settings/settings_shared.css

 /* 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. */
 
 /**
  * @fileoverview
  * Common styles for Material Design settings.
  */
 
+h2 {
+  color: #9e9e9e;
+  font-size: 100%;
+  font-weight: normal;
+  margin-bottom: 20px;
+  margin-top: 30px;
+}
+
+
+iron-icon {
+  color: #969696;
+}
+
 paper-button {
   margin: 0;
   min-width: auto;
 }
 
 paper-button[toggles][active] {
   background-color: LightGray;
 }
 
 .text-elide {
   overflow: hidden;
   text-overflow: ellipsis;
   white-space: nowrap;
 }
 
-h2 {
-  color: #9e9e9e;
-  font-size: 100%;
-  font-weight: normal;
-  margin-bottom: 20px;
-  margin-top: 30px;
-}
-
 .button-row {
   display: flex;
   margin-top: 25px;
 }
 
 .button-strip {
   text-align: end;
 }
 
 .list-frame {
@@ skipping 63 matching lines @@
 }
 
 .split .start {
   flex: auto;
 }
 
 .settings-box paper-item iron-icon {
   /* Same padding as paper-icon-button. */
   padding: 8px;
 }