A roan horse is one that has patches of white and patches a reddish brown hair because of jeans for the two hair colors are equally expressed..What is this an example of?

A roan horse is an example of codominance in genetics, where two different alleles for a trait are both fully expressed, resulting in a phenotype that displays characteristics of both. In this case, the reddish-brown and white hairs are both visible in the horse's coat, illustrating how neither allele is dominant over the other.