Not absolutely true for females. I actually find my females are more receptive during a shed cycle. My males will breed in the early stages of blue, but, when they are deep in blue...forget it.
"I've read that the breeding really starts after the cooling ends? If that's the case, I guess I don't have to worry. Atleast not yet."
The breeding at my place seems to peak in January (when I have been cooling for a couple months already) and females tend to ovulate when the temps com back up in February or later. Some will ovulate during the cooling period and it is critical to provide those girls a hot spot to cook their eggs during development.