- The warm/cool gene controls whether a cat's base color is warm (red, orange, yellow) or cool (green, blue, purple).
This gene is sex-linked to the X chromosome, so XX cats will have two copies (one for each X chromosome) and XY cats will have one copy. The W/w alleles act like O/o in real cats; an XX cat with a genotype of Ww would be a warm-cool tortoiseshell.
W - Warm
w - Cool
Y - Y chromosome
Real world comparison: Red vs. black vs. tortie (O/o/Y) in domestic cats
Base Color
- The base color gene controls what color(s) the cat's coat is based on.
Which color is expressed depends on the cat's warm/cool alleles. If the cat has a genotype of WW or WY, they will express the warm color (red, orange, or yellow). If the cat has a genotype of ww or wY, they will express the cool color (green, blue, or purple). If the cat has a genotype of Ww, they will express both colors in a tortoiseshell (tortie) pattern.
R - Red/green
rb - Orange/blue
rp - Yellow/purple
Red (1) can range from dark maroon to bright red. Colors should be relatively dark, as lighter shades are considered pink.
Orange (2) can range from dark amber to bright pumpkin. Browns are not allowed, but brown-tinted dark oranges are okay.
Yellow (3) can range from slightly orange shades to bright, almost neon yellow. 'Murky' yellows should be avoided.
Green (4) can range from forest green to bright green. Green-leaning turquoises are considered green.
Blue (5) can range from royal blue to cerulean. Blue-leaning turquoises are considered blue.
Purple (6) can range from dark eggplant to violet. Can be tinted slightly blue or red.
Real world comparison: N/A. Though it may be helpful to note that their dominance is in the order of the rainbow (with indigo/violet merged into purple). Also, the second letter in the recessive alleles 'rb' and 'rp' is the first letter of the cool color they control (rb - blue ; rp - purple).
Notes:
- Torties will always be a mix of complimentary warm and cool colors (the colors on the same allele).
Allowed tortoiseshell color pairings: Red-green, orange-blue, yellow-purple
Practice:
- WW Rrp // Answer: dfab red
wY rbrb // Answer: dmab blue
wY Rrb // Answer: dmab green
Ww rprp // Answer: dfab yellow-purple tortie
WY RR // Answer: dmab red
Ww rbrp // Answer: dfab orange-blue tortie
