RIP `#21759b`, the old WordPress Blue.

The final lingering instances were all for hidden accessibility helper text.

fixes #34388.


git-svn-id: https://develop.svn.wordpress.org/trunk@35340 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/css/common.css

@@ -144,7 +144,7 @@
 	font-weight: 600;
 	padding: 15px 23px 14px;
 	background: #f1f1f1;
-	color: #21759b;
+	color: #0073aa;
 	z-index: 100000;
 	line-height: normal;
 	-webkit-box-shadow: 0 0 2px 2px rgba(0,0,0,.6);

src/wp-includes/css/admin-bar.css

@@ -728,7 +728,7 @@ html:lang(he-il) .rtl #wpadminbar *  {
 	font-weight: bold;
 	padding: 15px 23px 14px;
 	background: #f1f1f1;
-	color: #21759b;
+	color: #0073aa;
 	z-index: 100000;
 	line-height: normal;
 	text-decoration: none;

src/wp-includes/js/mediaelement/wp-mediaelement.css

@@ -47,7 +47,7 @@
 	border-radius: 3px;
 	box-shadow: 0 0 2px 2px rgba(0, 0, 0, 0.6);
 	clip: auto;
-	color: #21759b;
+	color: #0073aa;
 	display: block;
 	font-size: 14px;
 	font-weight: bold;