I too have heard the theory that the autosomal red is linked to the salmon chest on the females, but I have heard people arguing against that as well. So I'm not sure what the right answer is. I think as long as we are watching for BALANCE- i.e. not silver looking but not very chestnut- we will be fine. I like it how we have it worded, "some chestnut permissible."
I don't know that I buy autosomal red (the dark red/chestnut on wing) is needed for salmon, but I do believe that gold/straw whatever you call it might be.