Okay, gold flights. Though there's only one gold right now, so...
Allow browns to chase?:
1. Only adult dragons can rise and chase, obviously. :)
2. Only one dragon can rise at a time; she cannot mate twice in a row. (Unless there's no other available golds.)
3. Only gold dragons can rise to mate. Bronzes and browns can chase them. Bronzes SHOULD be a lot more likely to catch the queen than browns, but...
4. The owner of the female chooses who catches her dragon, so she has the final say. The owner can also have a say in how many eggs are in the clutch, but has no control over who the hatchlings Impress.
4. Gold-Bronze matings can produce any color, Gold-Brown matings cannot produce queen eggs and have fewer bronzes, but more browns.
5. Golds participate in Threadfall, but are a little less likely to die, since little Thread gets through to them. Greens are assumed to chew firestone and fight Thread directly, which prevents them from mating to clutch.