This variety can only be created with the American mink gene, not the UK mink gene. Blue rats with the UK mink gene are lavender rather than platinum. The combation of genes makes what would be black on a regular agouti into the icy blue of the platinum, and the red banding is reduced down to a really pretty cream colour.
Genetics: Agouti with American mink, blue, and a modifier gene to pale the colour and eyes further (A-amamdd). The blue needs to be from pale (powder/American) lines rather than the darker British blue to get the right shade.
NFRS standard: 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.