One thing I've noticed about red tabbies is that their coloring is never predictable. My female red and white tabby has been the same color since I got her. My oldest male (1 year) lightened and lost his tabby stripes as he grew. Out of the four kittens I have, one has pretty much stayed the same up till now (5 months), his brother has gotten slightly darker and started devloping more stripes, another has gotten a LOT darker (6 months old) and his brother has gotten brighter and his stripes have gotten darker.