Highlight stickied comments; don't dim downvoted stickies.

The highlight color uses the same color as the subnav bar background
color. Make it a tad brighter so it's more visible.

app/assets/stylesheets/common/000_vars.css.scss

@@ -1,4 +1,4 @@
-$menu_color: #F7F7FF;
+$menu_color: #F5F5FF;
 $link_color: hsl(213, 100%, 50%);
 $link_hover_color: lighten($link_color, 25%);
 $link_dark_color: darken($link_color, 25%);