Tagging tracks in T4:
Let's tag tracks with multiple colors—like in the Mac Finder.
Coloring the entire track is useless because the colors don't stand out from each other. (and looks ugly as hell)
Tagging with different-colored "dots" would have the advantage of being able to color-code more than one association.
Simple, clean—Apple has been doing it this way for years, and it works great.