Has to do with the printing process, different colors are printed seperately. Maddux has 4 card #'s in 2007 M&M 12,13,14, and 15
I have these from that set:
Black of 12
cyan and yellow of 13
Magenta and 2 yellows of 15
There were so many cards printed in 07 M&M that there are at least 3 of each color per card number. 1 for the regular (white), 1 for the Black Parallel, 1 for the red parallel. I know in some instances people have found more than 3 of one color per card number. I am pretty sure one of the vlad collectors here has found that to be true, bdmac if iam remembering correctly.