We don't really have darker (or also called 'brown') tabby cats in Nintendogs + Cats, while they're actually very common. The closest we have to dark tabby cats is the grayish/brown tabby. I know there won't be updates on the game ofc. I would just like to discuss this topic :)
In this image is the type of tabby i'm talking about (the color that's sort of missing in-game)
It's my cat btw, his name is Chip :) Isn't he so cute? ♡