Several different genes (e.g. dun, cream, silver dapple and champagne) can dilute the basic coat colour of a horse.
At the cream dilution locus there are two possible allelic states: CCr and C. The semi-dominant allele CCr causes brightening of the basic coat colour which in single dose results in palominos, buckskins or smoky blacks and in double dose causes pale cream colours seen in cremello, perlino or smoky cream horses.
In contrast, the recessive allele C has no influence hair pigmentation. Animals being homozygous for allele C are non-dilute and show basic colours like chestnut, bay or black in the absence of other modifying genes.