That's what I ended up doing. My indigos and the bronze hens were to young to breed last year but this year I should get some out of them. The plan is to take the hens from that group and breed them to a Hazel cock. Hazels are definitely also a bronze+purple combo because when you breed Hazel to Indigo you get a 50/50 mix of Hazel and Indigo offspring (Josh Nelson told me about that one). To me that proves the two are both out of Bronze and Purple otherwise you wouldn't get either color from a pairing of the two.