E locus genes affect the hair shaft of various colors, which in turn can affect the surface pattern of a color.
Interestingly, steel is the most dominant of the E locus, but is not the most color found in the wild. In Steels, only the tips of the hair shaft will be colored.
Full Extension (E_)
Full extension is the most common (despite not being the most dominant) and is responsible for the natural wild agouti pattern in agouti rabbits.
Full Extension Colors
The harlequin gene causes patches of color that can either be brindled, blotchy, or in squared or barlike shapes. This gene is co-dominant.
Non Extension (ee)
In non-extension, the base color is wiped out and causes a fully colored rabbit. In agouti, this results in colors like Orange. In selfs and tan patterns, it also causes orange coloration, but leaves base color on the points (aka 'torting').
Non Extension Colors