DevTools: border and toolbar colors from Max's mocks.

Source/devtools/front_end/ui/tabbedPane.css

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2009 Anthony Ricaud <rik@webkit.org>
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  * 1. Redistributions of source code must retain the above copyright
@@ skipping 37 matching lines @@
 .tabbed-pane-placeholder {
     font-size: 14px;
     text-align: center;
     margin-top: 20px;
     text-shadow: rgba(255, 255, 255, 0.75) 0 1px 0;
 }
 
 .tabbed-pane-header {
     display: flex;
     flex: 0 0 27px;
-    border-bottom: 1px solid #dadada;
+    border-bottom: 1px solid #ccc;
     overflow: hidden;
     width: 100%;
     background-color: #f3f3f3;
 }
 
 .tabbed-pane-header-contents {
     flex: auto;
     pointer-events: none;
     margin-left: 5px;
     position: relative;
 }
 
 .tabbed-pane-header-contents > * {
     pointer-events: initial;
 }
 
 .tabbed-pane-header-tab {
     float: left;
     margin-top: 2px;
     padding: 2px 4px 2px 4px;
     height: 24px;
     border: 1px solid transparent;
     border-bottom: none;
     line-height: 15px;
     white-space: nowrap;
     cursor: default;
     display: flex;
     align-items: center;
+    color: #5a5a5a;
+}
+
+.tabbed-pane-header-tab:hover {
+    color: #333;
 }
 
 .tabbed-pane-header-tab-title {
     text-overflow: ellipsis;
     overflow: hidden;
 }
 
 .tabbed-pane-header-tab.measuring {
     visibility: hidden;
 }
 
 .tabbed-pane-header-tab.selected {
     border: 1px solid #ccc;
     border-bottom: none;
+    color: #333;
 }
 
 .tabbed-pane-header-tab.selected {
     background: white;
     border-top-color: #ccc;
 }
 
 .tabbed-pane-header-tab .tabbed-pane-close-button {
     display: inline-block;
     position: relative;
@@ skipping 87 matching lines @@
     cursor: pointer !important;
 }
 
 .tabbed-pane-shadow.vertical-tab-layout .tabbed-pane-header-tab.selected {
     color: inherit;
     border: none transparent;
     border-left: 6px solid #666;
 }
 
 .tabbed-pane-tab-slider {
-    height: 2px;
+    height: 1px;

[dgozman, 2015/06/12 18:56:17]

Is it enough? Probably makes it hard to tell which one is selected.

[pfeldman, 2015/06/12 19:35:29]

Lets give it a try. I am not a huge fan of it wither, but Max finds it more
elegant.

     position: absolute;
     bottom: -1px;
     background-color: #3E82F7;
     left: 0;
     z-index: 50;
     transform-origin: 0 0;
     transition: transform 150ms cubic-bezier(0, 0, 0.2, 1);
     visibility: hidden;
 }
 
 .tabbed-pane-tab-slider.enabled {
     visibility: visible;
 }
 
 .tabbed-pane-header.tabbed-pane-no-header-background {
     background-color: transparent;
 }