Coat color in cats is linked to gender. Calico cats have large patches of orange, black, and white fur. The genes for orange and black fur are found on the X chromosome, and for a cat to have both orange and black fur, it has to have two X chromosomes. Male cats have one X and one Y chromosome, so they have either orange or black fur, not both. A rare genetic condition, similar to Klinefelter's Syndrome in humans, can cause a male cat to have two X and one Y chromosomes, producing a male calico.