The trim-color house cats refers to all calicos... calicos are white spotted tortoiseshell cats. The "is orange or black" is a X linked gene, so you can have XoXb... and then the x chromosome inactivation kicks in and some groups of cells are activated orange and some are activated black.
But (not white) spots and variations of color get into things like the Agouti gene ( <a href="https://en.wikipedia.org/wiki/Agouti_coloration_genetics" rel="nofollow">https://en.wikipedia.org/wiki/Agouti_coloration_genetics ). A tabby cat (black and tan, or orange and darker orange) has no sex linked characteristics.
For a deep dive into the genetics of Agouti and how that influences cat fur colors, <a href="http://messybeast.com/genetics-agouti-and-corin.htm" rel="nofollow">http://messybeast.com/genetics-agouti-and-corin.htm
Female orange tabby cats are less common than males though, for much the same reason. They have to get the orange genes from both parents otherwise they are just calico.
The same is true of black cats, the other way around. There are fewer orange (or black) female cats because female cats have another option of coloring - tortoise shell (no spots) or calico (with spots). Another way of phrasing it, half of the male cats are orange, the other half are black - female cats have a third option.
Side bit - the wiki page for X chromosome inactivation shows a picture of a tortoise shell cat. <a href="https://en.wikipedia.org/wiki/X-inactivation" rel="nofollow">https://en.wikipedia.org/wiki/X-inactivation
And white spots gets into interesting questions of embryonic cell differentiation <a href="http://messybeast.com/bicolours.htm" rel="nofollow">http://messybeast.com/bicolours.htm
The "why are there large splotches of color with a calico cat compared to the much more mottled color pattern of a tortoise shell cat?"
<a href="http://messybeast.com/genetics-index.htm" rel="nofollow">http://messybeast.com/genetics-index.htm has a deep rabbit hole to go down (and that's for domestic cats... <a href="http://messybeast.com/wildcats-index.htm" rel="nofollow">http://messybeast.com/wildcats-index.htm for the other cats).
autoexec · · focus · HN ↗
Bonus pics: <a href="https://www.newscientist.com/wp-content/uploads/2026/09/SEI_312819149.jpg" rel="nofollow">https://www.newscientist.com/wp-content/uploads/2026/09/SEI_...
<a href="https://media.zenfs.com/en/live_science_953/73a4cafd69e9e86312a459e0206a1469.png" rel="nofollow">https://media.zenfs.com/en/live_science_953/73a4cafd69e9e863...
<a href="https://media.zenfs.com/en/live_science_953/1fea354ba7a8db696e3bc8750e32dca0.jpg" rel="nofollow">https://media.zenfs.com/en/live_science_953/1fea354ba7a8db69...
<a href="https://thepeninsulaqatar.com/get/maximage/20260917_1789662761-615.jpeg?1789662761" rel="nofollow">https://thepeninsulaqatar.com/get/maximage/20260917_17896627...
cromka · · focus · HN ↗
Also, they're only 3-4 lbs!
dotancohen · · focus · HN ↗
shagie · · focus · HN ↗
The trim-color house cats refers to all calicos... calicos are white spotted tortoiseshell cats. The "is orange or black" is a X linked gene, so you can have XoXb... and then the x chromosome inactivation kicks in and some groups of cells are activated orange and some are activated black.
But (not white) spots and variations of color get into things like the Agouti gene ( <a href="https://en.wikipedia.org/wiki/Agouti_coloration_genetics" rel="nofollow">https://en.wikipedia.org/wiki/Agouti_coloration_genetics ). A tabby cat (black and tan, or orange and darker orange) has no sex linked characteristics.
For a deep dive into the genetics of Agouti and how that influences cat fur colors, <a href="http://messybeast.com/genetics-agouti-and-corin.htm" rel="nofollow">http://messybeast.com/genetics-agouti-and-corin.htm
skipkey · · focus · HN ↗
shagie · · focus · HN ↗
Side bit - the wiki page for X chromosome inactivation shows a picture of a tortoise shell cat. <a href="https://en.wikipedia.org/wiki/X-inactivation" rel="nofollow">https://en.wikipedia.org/wiki/X-inactivation
<a href="http://messybeast.com/tricolours.htm" rel="nofollow">http://messybeast.com/tricolours.htm
And white spots gets into interesting questions of embryonic cell differentiation <a href="http://messybeast.com/bicolours.htm" rel="nofollow">http://messybeast.com/bicolours.htm
The "why are there large splotches of color with a calico cat compared to the much more mottled color pattern of a tortoise shell cat?"
<a href="http://messybeast.com/genetics-index.htm" rel="nofollow">http://messybeast.com/genetics-index.htm has a deep rabbit hole to go down (and that's for domestic cats... <a href="http://messybeast.com/wildcats-index.htm" rel="nofollow">http://messybeast.com/wildcats-index.htm for the other cats).