Change colors for charcoal and graphite sidebar themes

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

app/assets/stylesheets/framework/gitlab-theme.scss

@@ -88,8 +88,8 @@
 }
 
 $theme-blue: #2980b9;
-$theme-charcoal: #333c47;
-$theme-graphite: #888;
+$theme-charcoal: #3d454d;
+$theme-graphite: #666;
 $theme-gray: #373737;
 $theme-green: #019875;
 $theme-violet: #548;
@@ -100,11 +100,11 @@ body {
   }
 
   &.ui_charcoal {
-    @include gitlab-theme(#c5d0de, $theme-charcoal, #2b333d, #24272d);
+    @include gitlab-theme(#d6d7d9, #485157, $theme-charcoal, #353b41);
   }
 
   &.ui_graphite {
-    @include gitlab-theme(#ccc, $theme-graphite, #777, #666);
+    @include gitlab-theme(#ccc, #777, $theme-graphite, #555);
   }
 
   &.ui_gray {