Albinism is a mutation which prevents the body, either completely or partially, from producing melanin. Most of these genes attach to the same locus and thus form a series. A creature can only have two genes from this series at a time. They could be rr (two albino genes), cpcp (two colorpoint genes) or rcp (one albino gene and one colorpoint gene). But they cannot be rrcp because that's too many genes!
The currently available Albinism genes are all recessive. In order for one to show up, it must have two copies of the SAME gene. So rr (two albino genes) would show up as albino, but rcp (one albino and one colorpoint gene) would only be a carrier for albino and colorpoint while still appearing to have normal coloration
Must have two copies of the albino gene to show
ALL pigment (color) is entirely removed from the creature, including from the skin and eyes
The hair is clear, making it appear white
The skin shows blood undrneath because there is no pigment, making it look pink
Hard areas like claws and hooves will have a pink or yellowish hue, with no additional color to darken the keratin
The iris of the eye may appear pale blueish or yellow in dark areas, but will be vivid red in sunlight as blood reflects out. Even the pupil will be a dark red instead of black.
Albinos lack protective pigment, meaning their skin is much more easily sunburned, and their eyes are extremely sensitive to bright lights which can be harmful.
The iris is blue and the pupil is black, indicating the horse CAN produce pigment.
Markings are still visible on this zebra, it is not albino.
This bird is still has some pigment in its eyes and beak, it is just a pale color. It is not albino.