Saw a silly sports meme on reddit asking this question. I know there are more than a few exceptions to this but if you look at some Natty caliber teams the last 20-30 years or so, it kind of bears this out. 

Bama , Georgia , Ohio State, Indiana, Clemson, Oklahoma, FSU, USC, Texas (red or reddish family)

UK, Duke, UNC, Kansas, UConn, Florida, UCLA, (and hopefully not TTUN)  (blueish)

Peak off-season topic for sure but a little head scratching as well.