I've only ever had white ones, and I've read from a number of sources that they last the longest. ANY colors (including black) are the result of adding things to the plastic, and that causes them to wear down more quickly.My dad tried some with the graphite inserts like in 92' and they didn't seem to last any longer than regular ones. I read an article a while back in a magazine and it said that the white and colored ones wore out faster than black ones, I kinda call BS on that. if they are gonna wear out theyre gonna wear out. Track tension and riding conditions and how many idler wheels you have are the main factors in wear.