Final answer:
Most of the variation in coat color is explained by genetic factors.
Step-by-step explanation:
Most of the variation in coat color is explained by genetic factors. Different alleles can confer different coat colors, and these differences are encoded in an individual's genes and can be passed down to offspring. Genetic drift, phenotypic plasticity, and environmental factors can also contribute to some extent, but genetic factors play a major role in determining coat color variation.