there is nothing wrong with yellow - but if you spend a bit of time around here you will see an endless "debate" going on over red vs yellow. Traditionally, the 916/996/998 were red, and the 748 was yellow. The first 749 to come out was yellow, then they started supplying red ones.
Some bikes just "look right" in a particular colour - odd, but that's just the way it seems to be. Surprising the number of folk who agree too, on something that doesn't even make sense!
(of course - red ones are faster!)