The following information was authored by VetGen, who first established DNA testing for coat color.
"any breeding which produces both Brown or Cream, White, Apricot or red, has the potential to produce brown nosed cream, white, apricot or red. If the breeding does not have the potential to produce blacks, only cream, white, apricot, red and brown, all cream, white, apricot and red will have brown noses."
Brown nose is what you are all referring to as liver noses.
"any breeding which produces both Brown or Cream, White, Apricot or red, has the potential to produce brown nosed cream, white, apricot or red. If the breeding does not have the potential to produce blacks, only cream, white, apricot, red and brown, all cream, white, apricot and red will have brown noses."
Brown nose is what you are all referring to as liver noses.