diff --git a/app/helpers/watchers_helper.rb b/app/helpers/watchers_helper.rb
index d3b2a49b1..52f2ea119 100644
--- a/app/helpers/watchers_helper.rb
+++ b/app/helpers/watchers_helper.rb
@@ -169,14 +169,14 @@ module WatchersHelper
       if joined
         link_to text, {:controller => "courses", :action => "join_group", :object_id => "#{group.id}"},
                 :remote => true, :method => 'delete',
-                :id => "#{group.id}", :style => "padding: 8px 8px 4px; ",
+                :id => "#{group.id}", :style => "padding: 2px 8px 2px; background-color:#15bccf; color:#fff; ",
                 :confirm => l(:text_are_you_sure_out_group), :class => 'group_in'
 
       end
     else
       text = l(:label_new_join_group)
       form_tag({:controller => "courses", :action => "join_group", :object_id => "#{group.id}"}, :remote => true, :method => 'post') do
-        submit_tag text, class: "group_in", style: "width: 90px;height: 21px;"
+        submit_tag text, class: "group_in", style: "width: 90px;height: 21px; background-color:#15bccf; color:#fff;"
       end
     end
   end