This is exactly what I said above. I shot a track meet at the University of Iowa and because it was indoors and the lighting was even closer, I had bad shift in color just like yours. I get this at most of the high school basketball courts around here too.
Just something you have to plan on in PP.
Dont feel silly though. I thought I had a problem with my camera too.
I am very thankful for the responses. I read the link from Canon 10D. Very informative regarding catching the lighting cycles. I have never encountered those type of lighting issues before, so it threw me.