Heterochromia already exists in multiple forms in the game.

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;-;

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I love the idea!

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Thx <3

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Still the calico idea would be cool. Add in the variants of calicos, that can get rather cool. There's the normal versions and then the tabbied ones too!.
Ginger/red/orange & Black Calico
Dilute Calico
Chocolate Calico
Cinnamon Calico
Lilac-cream & White Calico
Fawn-Cream & White Calico

Though adding in the fact that in real life, calico's tend to be mostly female ( any males are about 99% sterile). so they could be rather hard to get, but also tend to breed some coat colors you wouldn't think of. (though that's mostly do to genetics and bloodlines.) I really like this idea, and though it might be a bit of work for the artist's it could be fun and might just be worth it.

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I support the calico but the half colored has already been vetoed. But supporting for the idea of calico markings

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