Fix contrast theme active button issue

Author: shakti97

client/styles/abstracts/_variables.scss

@@ -135,7 +135,7 @@ $themes: (
     toolbar-button-color: #333333,
     toolbar-button-background-color: #C1C1C1,
     button-background-hover-color: $yellow,
-    button-background-active-color: #f10046,
+    button-background-active-color: $yellow,
     button-nav-inactive-color: #a0a0a0,
     button-hover-color: #333333,
     button-active-color: #333333,