My wife's stepmom's parents have an old Bose Lifestyle system with white speakers. I just hooked up a new Samsung LCD ln52a630 for them and the white speakers really standout now. The easiest thing to do would be to replace the white speakers with black but it doesn't look like you can just buy the speakers. Can you hook up any other brand speakers to this system?
Realistically, the smartest option would be to sell the Lifestyle set (since it has good resale) and buy something that offers much better sound quality and will also blend in with the decor to their satisfaction. There are many options that have great WAF at less money.