Our team bikes are mostly white. Most people I know wipe down their bikes with Pledge Wipes after every ride. Frame, esp chainstays, head tubes and underneath the down tube. They're very handy and some people feel they make dirt easier to remove on later rides.

Since we're coastal we wipe down wheels/spokes as well. It doesn't take long and prevents weekly cleaning sessions from becoming a real chore.

Fizik Microtek bar tape also seems to be the easiest of the white tapes to keep clean. Keep an old hand towel on hand, soak the middle with Simple Green. Then grab both ends of the towel and buff the tape clean.

Total post-ride wipe-down only takes a few minutes.