American Blue is a color with many varients and modifiers. Like Mink, it seems to be highly influenced by carried recessives, making it a very malleable color. Shades of Blue from a deep steel-blue, often called "English Blue" to a pale almost-white-blue with dark eyes known as "Powder Blue," and a bright denim color commonly called "Sky Blue" are all expressions of this mercurial color. The modifiers which sway the color from steel to pale haven't been concretely identified, but rats will pass on their shading to their offspring, often making one breeder who concentrates on a single "shade" of blue identifiable simply by that shade.

All American Blue shades will have a lighter undercoat, sometimes as light as white, though the eyes remain black. There should always be a true "blue" tone to it, and it should never have heathering - the easiest way to tell Russian Silver from "Sky Blue." When moulting or in poor condition, Blues may "rust" or suffer from brownish patches of discolored fur.

a/a g/g

American Blue is a Black rat modified with all the red washed out of the hair pigment so that it appears blue-grey. Since other carried recessives can muddy or alter the color, an ideal American Blue line will try to breed out non-Blue recessive traits.

AFRMA

"Color is a slate blue, as dark as possible showing no brown patches or silvering. Eye color is dark ruby or black."

RSA

"Color: To be between a deep steel blue and a pale blue. Lighter shades have a pale silver base fur and underbelly. Darker shades to have a belly color matching the top, color may be lighter at the skin. Foot color to match the top. Faults: patchiness or rusting. Eye Color: Darker shades: Black / Lighter shades: Dark Ruby or Black."

RatsPacNW

"A slate blue color even to skin, black eyes."

URS

"A deep, slate blue with a pale undercoat. A darker shade is preferred over lighter blues such as "sky" and "powder". Faults: Light in color, rusting or dullness.

Eye Color: Preferably black, though light coloration due to dilutions in the genes may provide dark ruby eye color."

American Blue Rex Buck (c) Emily Evenson