In an inheritance pattern of codominance, we can see many phenotypes. We should begin by listing all the possible genotypes and associated genotypes:
Genotypes Phenotypes
D(H) D(H) H
D(H) D(R) HR
D(H) d H
D(R) D(R) R
D(R) d R
d d d
If we look at the phenotypes, there are two ways to get the "H" phenotype, two ways to make the "R" phenotype, one way to make the "HR" phenotype. and one way to make the "d" phenotype. That means there are four separate phenotypes possible.
