Originally Posted by katachtig
The color gene is carried on the X chromosome. In order for a cat to have black and orange, it must have two X chromosomes. In some cases, a male will be born with XXY chromosomes and thus is most like sterile.
I agree and want to add:
I don't consider black and white to be true "colors."
A color is found on the color wheel: red, orange, yellow, green, blue, indigo & violet.
Black, White and Grey are not included because they are not considered to be colors. White is all light and black is the absence of light.