This optical multi-color mouse from Trust can not only liven up your game of Excel Spreadsheets 2K7 with its colored top, it can liven it up with seven different colored tops. The MI-2300 has an exchangeable rubber top layer over the LED so you can coordinate to whichever color you're feeling today.
Angry? Try red. Horny? Try red again. Embarassed? Frustrated? Crimson? All red. There are of course, colors other than red, but the downside to those is that they're not red. Grab yours for $15.