That's interesting, re: color blindness and the roosters -
I wonder if you see the chestnut shoulders as black or gray?
How about the gold in the crest and saddle feathers?
Would it be accurate to say you see more monochromatic tones than specific colors?
If so, I think the way that would translate with the shoulders is they should have very small patches of dark areas, and the hackles and saddles should match each other in a lighter shade of gray. I think it might be difficult to differentiate the barring on the wings as to whether or not there is gold if everything tends to appear gray/brown.
The hens main visual would be high contrast between the hackle feathers and the body color; if they appear to be about the same shade of gray or brown or? then they are probably not cream.
Please keep posting =)