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Tonkinese - The Basic Colours © Linda Vousden Brown, Blue, Chocolate & Lilac or Natural, Blue, Champagne & Platinum There are many colours and patterns accepted in the UK but the colours described here are the foundation colours that are accepted by all Cat Fancy registration authorities who have granted the Tonkinese recognition. Anyone who wants to breed Tonkinese should have an understanding of how the colours are derived. However, if you just can’t get your head around genetics then try thinking of the basic colours as a simple family tree.
As far as Tonks are concerned Black is the dominant colour. However, due to the behaviour of colour in the genetic coat-colour group, to which the Tonkinese belong (i.e the albinism group), we don’t get a black coat we get a reduced version of Black ie. Brown
Two things can happen to the Brown to produce two more colours, each will be recessive to Brown.
The Brown is either :- modified, the pigment granule shape is very slightly changed allowing more light to pass through giving an even more reduced version of Black/Brown colour - Chocolate or diluted, instead of being evenly spread along the hair shaft the pigment granules form clumps, letting more light pass through the hair thus giving the appearance of Blue.
When you mate a pure modified Brown (ie. Chocolate)
with a pure diluted Brown (ie. Blue) you recombine the colours and,
- therefore the kittens will be Brown.
However, if you mate a Chocolate Tonk (that carries a dose of Blue dilution) with a Blue Tonk (that carries a dose of Chocolate modification) then you have a double dose of genes recessive to brown - the result is an even lighter version of chocolate with a bluish tone - i.e Lilac. Lilac is double-recessive to Brown.
Here’s the Wild Card - There is a gene called the Dilute-modifier, i.e. it only modifies dilute colours - Blue and Lilac (also Fawn, the diluted form of Cinnamon, which is not discussed here as it is not a UK Tonkinese colour). The effect is to slightly close up the pigment granules again so that less light passes through the hair shaft and the colours have a more Brown tinge i.e. Caramel. So, as far as we are concerned the Blue and Lilac are produced in the normal way and then modified to Caramel (see also the page on the Orange series to see the Dm effect on Cream). It may take longer for this colour to reveal itself, so the kittens may be initially mistaken for Blue or Lilac. In maturity the Caramel usually develops an attractive metallic-looking ‘glaze’ that is most noticeable over the forehead, back and hocks.
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