You will have to explain to me what you mean by they are not bred for color? Color is very important when you breed birds- so are you saying there are no varieties in Shamo. The APA recognizes three Ko Shamo standard varieties: black, dark and wheaten. I am sure there are others- white, birchen...
Just for information
Ko Shamo are a bantam Japanese breed
Shamo are a standard size Japanese breed
Up in the holler,
Your white bird may be a gene gold mine and may be able to provide some genes to diversify your birds. The crow winged male is birchen and could be used to make brown red or...