I don't think it would make any difference
- I have once bathed Harvey (gold) in black shampoo (was in a rush after a power cut
) and nothing changed
.
So I don’t think it would make any difference. You could use a black/whiting shampoo in one – which are available at most weebys like
hub. Which brings out both the black and the white colours out in the coat – I use one on Holly (blue).
HTH
Nikki x