There are a wide variety of dilution genes which affect base & modified colors.
DunDun dilutes the body hair of all base colors and is also responsible for a variety of primitive markings on the legs and body.
CreamA single cream gene dilutes all hair on bays and chestnuts. Two of them creates pure white animals with blue eyes and pink skin.
SilverSilver only affects black pigment, diluting black body hair to mouse grey and points to dark brown. Mane and tail go silver white.
ChampagneChampagne dilutes all base colors, creating animals with light eyes, mottled lavender-pink skin and sometimes a metallic sheen.
PearlOriginating in Iberian breeds, pearl requires a double dilution to have an effect on coat color. Can also cause pink spots on light skin.
MushroomFound mainly in Shetland Ponies, mushroom affects red pigment diluting it to a sepia tone. Mane and tail become cream or flaxen.
Light BlackA loose group of unexplained genetics surrounding black coat, skin and eye color variations. Possible undocumented dilution genes.