How rabbits can have more than two different coat colors

This is called co-dominance. It's when information from both alleles are expressed in the cell equally when you look at phenotype. Basically, two alleles are being dominant in the cell so they're working together much like a king and a queen helping run a country together.

Parent rabbits do not look the same, and since they sexually reproduce, their offspring is not an exact copy of the parent and therefore can contain different trait such as fur coat colors. I hope I helped!