Standard for Exchequer(plumage only): black and white evenly distributed. White in the surface color in the form of a large white blob as distinct from V-shaped ticking. Main tail feathers and primary and secondary wing feathers, mainly white, but half and half should be given preference. Undercolor: Dull black and sooty white evenly distributed.
Mottled (plumage only) Male:
Head:brilliant greenish black, one feather in three ending in a small v shaped tip.
Neck:Hackle brilliant greenish black, one feather in two ending in a small v-shaped white tip. Front of neck, same as breast. Back: same brilliant greenish black, one feather in four ending in a :-/shaped tip.
Saddle: same as hackle.
Tail: main tail-black, each feather ending in a V-shaped white tip. Lesser pickles and Coverts- black, each feather ending in a v shaped white tip.
Wings: Shoulders, fronts and bows- greenish black, one feather in three ending in a v-shaped white tip. Coverts-brilliant greenish black, each feather ending in a v-shaped tip, the whole forming two distinct bars across the wing. Primaries-black, ending in white tips.
Secondaries-lustrous black, ending with white tips.
Breast: Brilliant black, with one in two feathers ending in a v-shaped white tip.
Body and Stern: Body-same as breast. Stern-fluff, black tinged in white.
Undercolor, slaty black.
Whew! That was difficult. I will not do the hen unless you want me too. I will look into the genetics now. Please understand that both of these are from the ABA standard, so I could compare from the same book.