Index: src/wp-includes/css/buttons.css
===================================================================
--- src/wp-includes/css/buttons.css	(revision 28442)
+++ src/wp-includes/css/buttons.css	(working copy)
@@ -67,9 +67,7 @@
 .wp-core-ui input[type="reset"]::-moz-focus-inner,
 .wp-core-ui input[type="button"]::-moz-focus-inner,
 .wp-core-ui input[type="submit"]::-moz-focus-inner {
-	border-width: 1px 0;
-	border-style: solid none;
-	border-color: transparent;
+	border: none;
 	padding: 0;
 }
 
@@ -96,7 +94,8 @@
 	padding: 0 36px;
 }
 
-.wp-core-ui .button:active {
+.wp-core-ui .button:active,
+.wp-core-ui .button:focus {
 	outline: none;
 }
 
@@ -127,8 +126,8 @@
 	color: #555;
 	border-color: #cccccc;
 	background: #f7f7f7;
-	-webkit-box-shadow: inset 0 1px 0 #fff, 0 1px 0 rgba(0,0,0,.08);
-	box-shadow: inset 0 1px 0 #fff, 0 1px 0 rgba(0,0,0,.08);
+	-webkit-box-shadow: inset 0 1px 0 #fff, 0 1px 0 rgba( 0, 0, 0, 0.08 );
+	box-shadow: inset 0 1px 0 #fff, 0 1px 0 rgba( 0, 0, 0, 0.08 );
  	vertical-align: top;
 }
 
@@ -150,8 +149,8 @@
 .wp-core-ui .button.focus,
 .wp-core-ui .button:focus,
 .wp-core-ui .button-secondary:focus {
-	-webkit-box-shadow: 1px 1px 1px rgba(0,0,0,.2);
-	box-shadow: 1px 1px 1px rgba(0,0,0,.2);
+	-webkit-box-shadow: 1px 1px 1px rgba( 0, 0, 0, 0.2 );
+	box-shadow: 1px 1px 1px rgba( 0, 0, 0, 0.2 );
 }
 
 .wp-core-ui .button.active,
@@ -189,8 +188,8 @@
 .wp-core-ui .button-primary {
 	background: #2ea2cc;
 	border-color: #0074a2;
- 	-webkit-box-shadow: inset 0 1px 0 rgba(120,200,230,0.5), 0 1px 0 rgba(0,0,0,.15);
- 	box-shadow: inset 0 1px 0 rgba(120,200,230,0.5), 0 1px 0 rgba(0,0,0,.15);
+ 	-webkit-box-shadow: inset 0 1px 0 rgba( 120, 200, 230, 0.5), 0 1px 0 rgba( 0, 0, 0, 0.15 );
+ 	box-shadow: inset 0 1px 0 rgba( 120, 200, 230, 0.5 ), 0 1px 0 rgba( 0, 0, 0, 0.15 );
  	color: #fff;
 	text-decoration: none;
 }
@@ -201,16 +200,16 @@
 .wp-core-ui .button-primary:focus {
 	background: #1e8cbe;
 	border-color: #0074a2;
- 	-webkit-box-shadow: inset 0 1px 0 rgba(120,200,230,0.6);
- 	box-shadow: inset 0 1px 0 rgba(120,200,230,0.6);
+ 	-webkit-box-shadow: inset 0 1px 0 rgba( 120, 200, 230, 0.6 );
+ 	box-shadow: inset 0 1px 0 rgba( 120, 200, 230, 0.6 );
 	color: #fff;
 }
 
 .wp-core-ui .button-primary.focus,
 .wp-core-ui .button-primary:focus {
 	border-color: #0e3950;
-	-webkit-box-shadow: inset 0 1px 0 rgba(120,200,230,0.6), 1px 1px 2px rgba(0,0,0,0.4);
-	box-shadow: inset 0 1px 0 rgba(120,200,230,0.6), 1px 1px 2px rgba(0,0,0,0.4);
+	-webkit-box-shadow: inset 0 1px 0 rgba( 120, 200, 230, 0.6 ), 1px 1px 2px rgba( 0, 0, 0, 0.4 );
+	box-shadow: inset 0 1px 0 rgba( 120, 200, 230, 0.6 ), 1px 1px 2px rgba( 0, 0, 0, 0.4 );
 }
 
 .wp-core-ui .button-primary.active,
@@ -219,9 +218,9 @@
 .wp-core-ui .button-primary:active {
 	background: #1b7aa6;
 	border-color: #005684;
-	color: rgba(255,255,255,0.95);
- 	-webkit-box-shadow: inset 0 1px 0 rgba(0,0,0,0.1);
- 	box-shadow: inset 0 1px 0 rgba(0,0,0,0.1);
+	color: rgba( 255, 255, 255, 0.95 );
+ 	-webkit-box-shadow: inset 0 1px 0 rgba( 0, 0, 0, 0.1 );
+ 	box-shadow: inset 0 1px 0 rgba( 0, 0, 0, 0.1 );
  	vertical-align: top;
 }
 
@@ -234,7 +233,7 @@
 	border-color: #1b607f !important;
 	-webkit-box-shadow: none !important;
 	box-shadow: none !important;
-	text-shadow: 0 -1px 0 rgba(0,0,0,0.1) !important;
+	text-shadow: 0 -1px 0 rgba( 0, 0, 0, 0.1 ) !important;
 	cursor: default;
 }
 
@@ -310,7 +309,6 @@
 	}
 
 	/* Reset responsive styles in Press This, Customizer */
-
 	.wp-core-ui.wp-customizer .button,
 	.press-this.wp-core-ui .button,
 	.press-this input#publish,
@@ -325,7 +323,6 @@
 	}
 
 	/* Reset responsive styles on Log in button on iframed login form */
-
 	.interim-login .button.button-large {
 		height: 30px;
 		line-height: 28px;
Index: src/wp-includes/css/editor.css
===================================================================
--- src/wp-includes/css/editor.css	(revision 28442)
+++ src/wp-includes/css/editor.css	(working copy)
@@ -258,9 +258,13 @@
 }
 
 .mce-toolbar .mce-colorbutton .mce-preview {
-	margin-left: -17px;
+	margin: 0;
 	padding: 0;
-	width: 18px;
+	top: auto;
+	bottom: 2px;
+	left: 3px;
+	height: 3px;
+	width: 20px;
 }
 
 /* mce listbox */
@@ -570,6 +574,7 @@
 i.mce-i-underline,
 i.mce-i-alignjustify,
 i.mce-i-forecolor,
+i.mce-i-backcolor,
 i.mce-i-pastetext,
 i.mce-i-pasteword,
 i.mce-i-removeformat,
@@ -673,7 +678,8 @@
 	content: '\f214';
 }
 
-i.mce-i-forecolor:before {
+i.mce-i-forecolor:before,
+i.mce-i-backcolor:before {
 	content: '\f215';
 }