Lemon

Color male and female

Upper plumage a uniform, warm, light yellow, free of lighter shafts or flour-colored deposits.

Some black is permitted in the tail and flights.

The male's neck- and saddle-hackle, back, shoulders and the female's neck-hackle: a vibrant, warm, light yellow, somewhat darker than the breast color.

Down slightly lighter.

Serious faults

Distinctly different depths of color in parts of the plumage. Too much black, white or gray in the plumage or down.

Faults

The above serious faults occurring to a lesser extent and a down that is too light

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

Website with all available information regarding chicken genetics including the chicken color calculator.