Question of the Day – What Color is my Cat?

limr asks:

Ooh, I’d love to learn more about my two girls. They are sisters and I adopted them from a local shelter. They’d been found in a garage when they were about 2 weeks old, no sign of the mother. I got them at about 10 weeks. They are now a year and a half old. I’ve always wondered about how to describe them.

Zelda is all white with a patch of color on her head. It’s a mixture of grey, black, orange and tan. She also has a grey patch toward the end of her tail. Her pads and nose are pink, but she has a few black freckles on one or two of her paws.

Mrs.Parker is mostly brown and tan with black stripes and little patches of orange, the most prominent one being on the top of her head. Her paws and nose are black and she’s got a patch of orangy-pink on one of her paws.

Let’s look at a photo:

Mrs Parker is to the left, and Zelda is on the right.  The first key to determining real color is to realize that cats have a maximum of two major pigments, and many only one.  This is a black and an orange.  Other tints and shades are combinations of the others or modifications such as dilute or the fading done by the pointed genes.

Mrs Parker looks to be a pretty standard tortoiseshell cat, so she has both black and orange regions on the body. She shows stripes on the black areas, so she is a ‘calitabby’.  The blacks are two intense for any dilution. So I would interpret the named colors to be:

1. Black – the tabby stripes on a black region (o gene active).
2. Orange – the tabby stripes on an orange region (O gene active).
3. “grey” – agouti hairs in a black area.
4. “tan” –  agouti hairs in an orange area.

Mrs Parker shows no sign of White Spotting (s/s)

Zelda appears to be ‘colored’ very differently, but this seems to me to be mostly illusion. She has a large amount of spotting, probably a double S/S and large ‘volume’ on the polygenes.  She’s more than L9 and the Van, with color on the head alone, aside from a few spots.

But looking at the colors aside from the white, Zelda seems very similar to her sister. If you block out the white areas and look only at the colored region, she looks to be a calitabby like her sister. The black regions have a black stripe. The grey “ring” looks to be part of a tabby tail, but only the ‘between stripe’ color is visible.

If you imagine Mrs. Parker being white except for one or the regions between the ring stripes on the tail, it would look grey instead of tabby.  Presumably those are ‘agouti’ hairs and each one will show bands of black on a grey or brown background.

The paw colors are pretty typical – White Spotted cats have pink, and normal colored areas have black or orange depending on the nearby skin color.

In order to get a ‘all white’ and ‘no white’ pair, each parent would need to have only one White Spotting gene (S/s).  Mrs Parker got both ‘s’, and Zelda got both ‘S’.  Presumably they would have each been pretty high white – ‘cow kitty’ or ‘cap and saddle’.  This guess is based on Zelda’s high white – both parents probably had more white than average for a single white spotted cat to give so much to their kitten. All we know about color is that both parents were not all orange or all black.

Mrs Parker’s Genes

Locus	Genes	Notes
Black	B/-	“Black”
Orange	O/o	Tortiseshell
Tabby	T/-	Mackerel Tabby
Agouti	A/-	Agouti
Dilute	D/-	No Dilution
Long Hair	L/-	Short Hair
White Spotting	s/s	No white spotting

Zelda’s Genes

Locus	Genes	Notes
Black	B/-	“Black”
Orange	O/o	Tortiseshell
Tabby	T/-	Mackerel Tabby (probably)
Agouti	A/-	Agouti
Dilute	D/-	No Dilution
Long Hair	L/-	Short Hair
White Spotting	S/S	White spotting L9+

What makes the determination of color confusing is the simple ‘real’ color can be modified in practice by masking with white, faded in one way be pointing genes, faded in a different way by dilution, and overlayed with different hair patterns like agouti. The same way a newsprint photo or an old tv screen could make all the colors out of three colored dots in different patterns, the cat takes two pigments and no pigment combined in different ways to make all the colors a cat can have.