Yes blues and albinos do occur naturally but the reds are not genetic morphs they are local specific color variety's. If you breed a genetic blue or an albino to a normal you get normal hets for the color. If you breed a red or other local color variety it just washes out the red. There is alot of color variation in iguana iguana throughout the range, some are green some are almost black some are almost yellow even green with bright orange faces. most reptiles with large ranges have alot of color variability.
just look at bearded dragons or rosy boas but theses are not genetic color morphs.
Rob