Color and pattern male

Plumage: warm red ground-color, each feather  three or four times crosswise interrupted by a slightly arched, light creamy-colored, bar which is not sharply defined; color and pattern should be as uniform as possible over the entire body, some grey in tail and wing-flights allowed.

Ornamental feathers: the number of crosswise bars is greater in proportion to the feather's length and tends towards an inverted V, most notably in the hackles.

Cuckoo males are allowed in either purebred or impurebred:

- Purebred, the lighter bars are distinctly wider than the red bars, creating an overall light appearance.

- Impurebred, the lighter bars are distinctly narrower than the red bars, resulting in an overall darker appearance, similar to the female.

Down: light red to creamy white without barring, some grey allowed.   

Serious faults

Greyish discoloration on back, shoulders, wing-bows and saddle-hackle. White wing-bay. Whitish breast.  Absence of barring in feather-veins and tail.

Faults

Brown-grey or dark-grey in the tail-feathers. Some greyish discoloration in the hackles.

Color and pattern female

Plumage: as for the male, but the barring somewhat fainter; some greyish shaft-stripes with cuckoo pattern are allowed at the lower part of the neck-hackle.

Down: light red to creamy white without barring, some grey allowed.      

Serious faults

Complete absence of barring. Greyish discorolation on back, shoulders, wings and saddle. Absence of barring in feather-veins.

Faults

Brown-grey or dark-grey in the tail-feathers. Some greyish discoloration in the hackles.

Genetic code: https://kippenjungle.nl/Overzicht.htm

Website from Henk Meijers with all available information regarding chicken genetics including the world famous 

Chicken Color Calculator