Just what is marble cheese?

I’ve heard it’s cheddar and mozarella, cheddar and white cheddar, chedder and bleached cheddar, and a slew of other things. Does anyone know just what the two types of cheese are in marble?

AFAIK, its Colby and Monterrey Jack.

Another thing: Colby is the orange.

I’ve seen Colby Jack marble, Cheddar Jack marble and Cheddar/White Cheddar marble. I imagine they could “marble” together any two cheeses they felt like these days.