Fix issue #579

build/less/navs.less

@@ -74,6 +74,9 @@
       > a {
         color: #444;
         .border-radius(0);
+        &.text-muted {
+          color: #999;
+        }
         &,
         &:hover {
           background: transparent;

dist/css/AdminLTE.css

@@ -2456,6 +2456,9 @@ a:focus {
   color: #444;
   border-radius: 0;
 }
+.nav-tabs-custom > .nav-tabs > li > a.text-muted {
+  color: #999;
+}
 .nav-tabs-custom > .nav-tabs > li > a,
 .nav-tabs-custom > .nav-tabs > li > a:hover {
   background: transparent;