TP Recommended Themes Series:
This is what I'm using on my Nokia N8 right now --
It features a Blue-Violet gradient background and has these cute multi-colored neon icons.
The name is "Fresh" and you can get it now for free via the Ovi Store. Just go to Ovi Store, log-in to your account and search for 'Fresh', this theme should be the first item in the results. Download and install.
Then, go to your phone's Settings. Click on Themes. Go to General option, then choose Fresh.