Primary Lines: 4-Square, Cinnamon, Blue Agouti
Agouti has an overall brown appearance, though the beauty and subtlety of this color type are far more nuanced than simply "brown". Agouti is a dominant gene on the A-locus, represented by the upper case "A". A single agouti gene will result in an agouti rat.
The Agouti gene controls whether the rat's hairs are banded or solid in color. In the standard Agouti rat the base of each hair is gray, followed by a golden band and a black tip. Various factors can result in Agouti rats that have wider golden bands or shorter, for an overall lighter or darker appearance.