Labrador Retriever coat colour genetics fur colour but those with black skin can potentially produce a Dudley. Dudleys breed true for both fur and skin. The ability of the E locus to override the coat colour directed by the B locus is a classical example of epistasis, where multiple genetic loci affect the same observed trait. The E locus also determines whether the phenotype due to the third genetic locus affecting coat colour will be evident. This locus is recognised as affecting coat colour through the expression of pheomelanin, the pigment responsible for red and yellow pigmentation. The effects on pheomelanin pigmentation are only seen
Pigment chemicals also have their own reflection and absorption patterns, which can affect the final spectrum. For example, in pigment/binder mixtures, individual rays of light may not encounter pigment molecules and may be reflected unchanged. These stray rays of source light make the mixture appear to have a less saturated color. Pure pigment allows very little white light to escape, producing a highly saturated color, while a small quantity of pigment mixed with a lot of white binder will appear unsaturated and pale due to incident white light escaping unchanged. Naturally occurring pigments such as ochres and iron oxides have been