Mutations

Unless otherwise noted, each exists in its own series. If two genes could coexist, such as polydactyl (extra toes) and albino (no pigment), both can be present on the creature.
Mutations are changes or damage done to genes which causes them to appear different from normal*
MOST mutations can be inherited, others cannot be passed down to offspring
Unlike regular markings, Mutations may not have their genetic series identified, and have a RARE chance to appear spontaneously in a newborn even if neither parent has them*

Realistically speaking, ALL inheritable genes and coat colors are the result of mutations, which were passed on to offspring until they became commonplace. Mutations here are simplified to mean unusual coats, markings, or physical traits which can appear spontaneously at birth without either parent carrying a gene.

Color Mutations

While most mutations exist in their own series and creatures can carry multiple mutations, some mutations are more dominant than others and will cover up "weaker" ones.
Mutation genes have a hierarchy which determines which will show up if they compete for the same area. (i.e. albino will always cover over melanistic) IF two genes could coexist, such as Axanthic (red coloration is removed) and Erythristic (black coloration is diluted), both can be present on the creature.

The hierarchy, from most to least dominant is: Chimeric, Vitiligo, Starmark, Albino, Color-Point, Ocular Albinism, Bend Spot, Axanthic, Erythristic, Melanistic, Pseudomelanistic

Chimeric | / & /

Vitiligo | ??

Starmark | ??

Albinism Series

Albinism is a mutation which prevents the body, either completely or partially, from producing melanin. Most of these genes attach to the same locus and thus form a series. A creature can only have two genes from this series at a time. They could be rr (two albino genes), cpcp (two colorpoint genes) or rcp (one albino gene and one colorpoint gene). But they cannot be rrcp because that's too many genes!

The currently available Albinism genes are all recessive. In order for one to show up, it must have two copies of the SAME gene. So rr (two albino genes) would show up as albino, but rcp (one albino and one colorpoint gene) would only be a carrier for albino and colorpoint while still appearing to have normal coloration