I didn't think I cared, until I bought my current bike. I always thought it looked kind of dull (it's almost all black), so when I had to change the handlebar tape recently, I went with yellow and also added a yellow seat bag. It's amazing how much those two little changes played up the subtle yellow stripe on the frame. Even more surprising is how much more I like my bike now that it looks just a little snazzy. I wouldn't want anything too bright or girly or attention grabbing, but apparently I do prefer a little bit of style.