Codominance is when organisms of different colors have offspring and the offspring has a clear appearance of each color. Codominance is a relationship between two versions of a gene. Individuals receive one version of a gene, called an allele, from each parent. If the alleles are different, the dominant allele usually will be expressed, while the effect of the other allele, called recessive, is masked. In codominance, however, neither allele is recessive and the phenotypes of both alleles are expressed.
Incomplete dominance is when organisms of different colors have offspring but instead of both colors showing they are equal in cominance and mix. Incomplete dominance is a form of intermediate inheritance in which one allele for a specific trait is not completely expressed over its paired allele. This results in a third phenotype in which the expressed physical trait is a combination of the phenotypes of both alleles. Unlike in complete dominance inheritance, one allele does not dominate or mask the other allele. Incomplete dominance occurs in the polygenic inheritance of traits such as eye color and skin color.
