American shorthair cats come in more than 80 colors and patterns. There are multiple variables in cat-coat genetics, some of which are gender specific. In general, female cats have more fur variations than their male counterparts. Silver tabbies are the most well-known American shorthair variety.
Familiarity Breeds Color Content
The Cat Fanciers' Association first recognized the American shorthair cat as one of its first five-registered breeds in 1906. They were called domestic shorthairs until they were distinguished as American shorthairs in1966.
The ancestors of the American shorthair were probably domestic European cats, who dispersed across the New World after earning their keep as rat assassins aboard ships in the 18th century.
The breed has a large palette of coat colors and patterns -- more than 80 varieties total -- but American shorthairs share other characteristics. They have well-balanced physiques, robust health and quiet, amenable dispositions.
Despite their diversity, multiple cat fancier groups and breeders distinguish the silver classic tabby as the the most well-known variety of American shorthairs. Many others are bred for dramatic contrasting patterns with painted faces.
The Cat Fanciers' Association's 2010 breed point sheet for American shorthairs lists 42 broad color classes -- for reference purpose, not show standards -- which play out in twice as many varieties. These broad categories include combinations and variations of whites, blues, blacks, reds, creams, silvers, smokes and browns. Tabby stripping is another significant distinction.
The Color and the Shape
An alphabet of genetic variables affects a cat's coat color, American shorthairs included. The genes for orange or black fur and the genes for unpigmented -- aka white -- fur create basic distinctions, while other genes dilute pigmentation. Some genes, for instance, turn orange to cream and black to gray (cat breeders call it blue).
Other genes affect patterns -- technically, they influence pigment disbursement -- resulting in striped, mottled or solid coats. This is complicated by dominant, recessive and carrier genes, yielding far-flung furs.
In some senses, American shorthairs are a rarefied form of their domestic shorthair brethren, the mutts of the cat world.
A given domestic shorthair may share the characteristics of an American shorthair, but that's no guarantee her offspring will turn out the same. The domestic shorthairs' gene pool is much larger, thus the potential for deviations from the American shorthair archetype is great.
If you're looking for a purebred American shorthair, make sure it has verifiable lineage papers.