As well being of the correct colour, the rat should also comply with the General Standard of Excellence. This is the general shape and appearance which all exhibition rats should possess. The eyes shall be round, bold, clean and of good size. The tail shall be cylindrical and as long as the body, thick at the base, tapering to a fine point. The ears, feet and tail shall be covered with fine hair.
Bucks are longer than does and have a harsher coat.
Poor health and condition, bare patches, kinked or short tail, and scaly ears are all considered serious faults .No whiskers, severe scabs, fleas or mites, very obvious ill health, and a lack of tameness are reasons for disqualification . Any coloured hairs to be severely penalised. Base fur to be black. Foot colour to match top. To be an even mid grey-brown, devoid of dinginess, silvering or patches and having a distinct bluish sheen.