White bluetail

Color and pattern male

Plumage: completely white except for the bright blue pattern on the primary- and secondary-flights and the bright blue tail feathers; a few small blue feather tips are permitted at the lower neck-hackle, which must not degenerate into a greater blue tip.

Primary-flights: bright blue with a white edge, which should be sharp and not too broad. 

Secondary-flights: bright blue with a wide white edge on the inner vane, outer vane white, so that when the wing is closed it is almost entirely white.

Tail: steering-feathers bright blue, the sickles are bright blue with a white edge, and the shafts are light; In contrast, most males have such a wide white edge on the shorter sickles that they are predominantly white.

Down: white or gray, but gray down must not penetrate the top color.

Serious faults

White patches on the tail steering- feathers. Absence of bright blue on the wing-flights. Blue feather tips at the lower neck-hackle or a distinct striped pattern. Some yellow tinge in neck, saddle and shoulders.

Faults

Too much white on the large sickles. Insufficient pattern on the wing-flights. Blue color much too dark or much too light. Many black splashes in the blue feathers. Very uneven blue color.

Color and pattern female

Plumage: completely white except for the bright blue tail steering-feathers; a few small blue feather tips are permitted at the lower neck-hackle, which must not degenerate into a greater blue tip.

Primary- and secondary-flights: similar to those of the male

Tail: steering-feathers bright blue, except the top feathers on each side, which must have a narrow, sharply defined white edge; a narrow white edge on the other steering-feathers is permitted; coverts bright blue with a narrow white edge; completely white coverts are permitted.

Down: white or gray, however, gray down must not penetrate the upper color.

Serious faults

White patches on the tail steering-feathers. Absence of bright blue on the wing-flights. Yellow tinge. Blue feather tips at the lower neck-hackle or a distinct striped pattern.

Faults

Too broad white edging on the tail steering-feathers. Insufficient pattern on the wing-flights. Too dark or too light blue color. Many black splashes in the blue feathers. Very uneven blue color.

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

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