Siamese - Blue Tortie is recessive to Tonkinese - Blue Mink Tortie
Sashimi, a Tonkinese - Blue Mink Tortie bred with Boyden, a Siamese - Blue Tortie
Their baby was Phee Phee a Tonkinese - Blue Mink Tortie
She bred with Avidor a Tonkinese - Blue mink, a fur known to be recessive to both and they produced a Siamese - Blue Tortie, since Avidor cannot hide that fur Phee Phee must have so Siamese - Blue Tortie is recessive to Tonkinese - Blue Mink Tortie.