Then there are the genes we can all recognize that affect the bay coat. Genes like the cremello gene which when present in the heterozygous form produces the buckskin and when homozygous the gene produces the perlino . The resulting color of buckskin will depend on the original bay coat and modifiers. Deeper red bays will produce richer colored buckskins, etc. The dun gene is very similar to the cremello gene in that it dilutes the coat color but not the point color, it produces lineback duns that look very similar to buckskins.
Geneticists disagree on whether dorsal stripes are a requirement for duns.
Please don't call them paints , that name is used to describe a pinto Quarter Horse. Breeders MUST learn to identify this color if they will ever be able to predict the colors of their foals. A couple of other genes that can drastically affect bays are grey and roan . These two genes are also often confused, especially in terminology, by not only miniature breeders but horse breeders in general. Since both start off full colored as foals, it is easy to see why there can be mistakes made in registration.