Body colour to be a rich ‘clotted’ (warm) cream colour with no odd coloured hairs or patches. Belly colour to be pale cream, demarcation between top colour and under to be allowed. Ears and tail to be pink. Eyes: pink or black.
Genetics: genetics currently unproven and being researched, but appears to be a recessive modifier.
To be a rich, golden fawn evenly ticked with silver guard hairs. Undercolour to be pale blue/grey carried down to the skin. Belly fur to be creamy silver. Top colour to be even carried well down the sides with clear differentiation between belly and top colour. Any tendency to sootiness or greyness of the top colour to be penalised. Eyes to be dark ruby (as dark as possible).
Genetics: A/- r/r or A/- b/b r/r
To be a rich orange fawn, evenly ticked with silver guard hairs. Belly fur to be white. The demarcation between the top colour and white belly to be sharp and clear cut, devoid of irregularities and brindling. Eyes red.
Genetics: A/A p/p
To be of a recognised coat colour (black, mink, chocolate and British blue only), the coat containing equal numbers of silver and non-silver guard hairs. Each silver hair to have as much of its length white as possible, a coloured tip to be allowed. Silvering to give an overall sparkling appearance. It should not be possible to confuse a silver with a Pearl or a Self. Foot colour to match top. Belly colour on other silvered varieties to match top.
Genetics: This is not due to a silvering gene, but selection for white hairs.
To be a rich ruddy brown, evenly ticked with black guard hairs. Base fur dark grey to black. Belly fur to be silver grey. Foot colour to match top. Eyes black.
Genetics: A B C D P R M. Rats heterozygous for B, M and P sometimes have better colour. Rats heterozygous for R may be insipid while rats heterozygous for D are dull.
To be a warm russet brown, evenly ticked with chocolate guard hairs. Base fur mid-grey. Belly fur as Agouti but of a lighter shade. Foot colour to match top. Eyes black.
Genetics: A/- m/m
An attractive blend of mid-blue ticking over a medium fawn ground. Undercolour to be blue down to the skin. Belly colour silver. Feet dove grey. Ears and tail to be covered with blue hairs. A brown tinge will be judged as a fault. Eyes black.
Genetics: A/- d/d
To be an attractive blend of dove grey ticking over a medium fawn ground. Undercolour pale grey down to the skin. Belly colour silver. Feet dove grey. Ears and tail to be covered in grey hairs. Pinky tinge desirable, blue tinge a fault. Eyes very dark ruby to black.
Genetics: A/- b/b R/r m/m
To be palest silver, shading to creamish undercolour. Each hair to be delicately tipped with grey evenly over the whole animal. Belly fur to be creamy silver. Foot colour to match top. Eyes black.
Genetics: a/a m/m Pe/pe (pearl is dominant lethal gene)
Coat to consist of three bands of colour from the base up - cream, blue and orange, with silver guard hairs, to give an overall golden appearance with a silver sheen. Belly fur pale silver grey. Foot colour to match top. Eyes black.
Genetics: A/- m/m Pe/pe (pearl is dominant lethal gene)
A bright blend of pale grey ticking over a rich cream ground, with a distinct ice-blue hue. Undercolour pale blue down to skin. Belly colour pale silver. Feet pale grey. Eyes red to ruby. Strong blue or brownish tones a fault.
Genetics: Combination of an unrecognised brown gene (called American mink) with blue and another unrecognised pink eyed gene. This is the agouti based version.