MD Settings: change disabled select visuals.

ui/webui/resources/html/md_select_css.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-styles/color.html">
 
 <dom-module id="md-select">
   <template>
     <style>
       .md-select {
         --md-arrow-width: 0.9em;
         -webkit-appearance: none;
         /* Ensure that the text does not overlap with the down arrow. */
@@ skipping 14 matching lines @@
         outline: none;
         padding-bottom: 3px;
         padding-top: 3px;
         width: var(--md-select-width, 200px);
       }
 
       /* Mirroring paper-dropdown-menu disabled style. */
       .md-select[disabled] {
         border-bottom: 1px dashed var(--secondary-text-color);
         color: var(--secondary-text-color);
-        opacity: 0.33;
+        opacity: 0.65;
         pointer-events: none;
       }
 
       :host-context([dir=rtl]) .md-select {
         background-position-x: 3%;
       }
 
       .md-select-underline {
         border-top: 2px solid var(--google-blue-500);
         display: block;
         position: relative;
         top: -1px;
         transform: scale3d(0, 1, 1);
         transition: transform 200ms ease-in;
         width: 100%;
       }
 
       .md-select:focus + .md-select-underline {
         transform: scale3d(1, 1, 1);
         transition: transform 200ms ease-out;
       }
 
       .md-select-wrapper {
         display: inline-block;
         max-width: 100%;
       }
     </style>
   </template>
 </dom-module>