Beer and Pet Colors

If I feed a pet a beer where the pet goes back to its first stage, is the color I get from the pet random or will I just get the same color?

If the color I get isn't random, I'd like the ghost cat from the kennel and to give it a beer. If it is random, I'll think about it.

No I think your pet will stay the same as it is, it'll just go back a level or two. For example if you get a red dragon it will always be red no matter what you use on it, unless you use the absinthe potion which changes a pet to its other colour, or gender.