adjusted sidebar label color

resources/less/metager/parts/sidebar.less

@@ -55,7 +55,7 @@
                 font-weight: normal;
                 text-decoration: none;
                 text-indent: 12px;
-                color: black;
+                color: @text-color;
                 line-height: 20px;
                 display: inline-block;
                 width: 100%;