Dilutions of black:
dun x blue is known to me, blue goes to the outer end of the bird, dun inner sides counted from the middle of the bird that's located roughly halfway the breastbone and then into the center of the bird. So dun coloured bird and tail and wings (& foot feathers and or crest) are half blue half dun.

How about dun x chocolate (Carefoot's), which colour is stronger?
How about blue x chocolate (Carefoot's)?
Did anybody try this?