The real story
The orange colour gene sits on the X chromosome. A male cat (XY) needs only one copy to be orange, while a female (XX) needs it on both. That's also why tortoiseshell and calico cats, which mix orange and black, are almost always female, because they need two different X chromosomes.
In 2025 two research teams, in Japan and at Stanford, finally found the mutation behind it: a small deletion that switches on a gene called ARHGAP36 in pigment cells. Nothing like it is known in other mammals. In Indonesia, the orange cat has a different reputation: online, 'kucing oren' is the neighbourhood troublemaker who fights, steals fish and naps on every motorbike.
