The Oriental Shorthair is the most genetically unrestricted of the Siamese-family breeds, accepting virtually every color and pattern combination expressible in the 11-locus feline genetics matrix, including all B-locus alleles, the full Inhibitor (I) locus silver and smoke series, all tabby patterns, and all O-locus tortie combinations — but critically, without the colourpoint restriction that defines SIA. EMS codes for OSH span non-agouti solids, all four tabby patterns, bicolors, and pointed variants (Colourpoint Orientals, formerly registered separately), making a comprehensive EMS color calculator essential for managing the enormous combinatorial space. Feline genetics programs for OSH benefit from systematic locus-by-locus carrier analysis given the simultaneous segregation of B, bl, b, d, O, I, cs, and S alleles within the population.
Common recessive carriers
All color-locus recessives are present in OSH populations: chocolate (b), cinnamon (bl), dilution (d), and colourpoint (cs). The O locus produces red, cream, tortie, and torbie variants. Inhibitor (I) locus produces silver, smoke, shaded, and tipped phenotypes in all base colors. Oriental Colourpoints (cs/cs) are accepted within the OSH register in FIFe.
Breed-specific restrictions
No significant color restrictions apply to the Oriental Shorthair under FIFe standard. Dominant White (W) is accepted. Amber (e) is not listed for OSH in FIFe standard. All tabby patterns are accepted. The colourpoint (cs/cs) Oriental is included in the OSH register. Bicolors are accepted, though white-spotted (S locus) Orientals are less common in the show ring.
Pattern quirks
All four tabby patterns (22, 23, 24, 25) are accepted. Ticked tabby (25) is common and breed-typical in the OSH. The 'Foreign White' is a separate FIFe registration (OFW) for white Orientals — W/- cats — and is not coded as OSH in EMS. Silver tabbies, smokes, and shaded phenotypes are all common in OSH show lines.
OSH nBlack (solid)OSH b 25Chocolate Ticked TabbyOSH ns 24Black Silver Spotted TabbyOSH a 33Blue Colourpoint (Oriental Colourpoint)OSH fBlack Tortie (solid)OSH c 22Lilac Classic TabbyFree online tool to predict kitten coat colors based on Mendelian genetics. Select the breed and appearance of sire and dam to see color probabilities.
Enter the appearance of both parents to calculate color predictions.