Although I kinda like the colors for tabs, I think it's overkill to have different colors on different servers. To be hounest, I think the name of the machine you're working on (on the left) is clear enough when working with it.

The only thing I tend to dislike in screen, is that it's rather tedious hitting ^a A to rename the screen. If anyone knows how to accomplish auto-renaming, I'd be happy to hear :)