The colors you refer to are usually called Strains. Different strains of discus can breed together without any problems yes. Still the same species, just a different color morph (strain). Not to mention that the pair has to acctually like each other.
However, discus breeding is a bit more complicated then just getting a male and female. Its very unlikely they will breed, or breed sucessfully in a normal tank not setup for breeding specifically. It takes large amounts of water changes and certain water specs (pH, Temp, etc) to breed them sucessfully, which might not be good for your plants or other fish. And they won't usually do it in the community type setting. Its why breeders dedicate smaller tanks to each pair by itself.