You could program green for those you always want to talk to, and red for those you don't. Purple could let you know that it's your best friend or maybe blue could be for that special guy with the to-die-for eyes of the same hue.
Perhaps most importantly when the phone is ringing the system automacially scrolls between all of the color to alert you that the caller ID is unidentified or blocked because no one really wants to speak to telemarketers or psycho ex-friends.
Once again color adds another dimension to a familiar product. Just make sure I don't find my number coded with your "do not answer" color.
Available at Brookstone.com