I signed in to my Gmail and saw a message at the top telling me of new themes which were available immediately. No more needing scripts and hacks to change the appearance of Gmail! There’s quite a few, but probably the most interesting is the theme named Terminal:

I like them! “Terminal” looks a lot better (no grey) but obviously I have to protect my email address and emails. You can read more about themes over at this Gmail blog post. I’ve got to hand it to them, they’ve been very busy lately.