Curiously, very few cards of a color had the color listed in the name. At one point, the only thing that colored a card was the color of the mana required to cast it, or if the color was listed in the rule text.

Some black creatures turned colorless when they hit the table. (Some green cards painted green anything they intereacted with). And blue had some spells that would change other cards swapping out rules targeting colors or land types. So a protection from black could be turned into protection from green or whatever.

One of the seasons got really into color interaction but by then I had gone sober.