Groups page could be clearer on which groups one is subscribed to

At the moment the groups page shows a full list of groups with a button beside each: either Subscribe or Subscribed. It's not very clear, at a glance, which ones are subscribed as there is no colour difference and the terms differ only by the last letter. I personally think it would be better if it showed 'unsubscribe' for the ones you're already subscribed to, and even better if this were in green.