"Breeding the Diamond Dragon is completely random out of the four elements. You need to ensure you have fire, air, water, and forest within your breeding combination. In color terms you need red, yellow, blue, and green within the pair of dragons you choose to breed. Confirmed working combination is island dragon and firestorm dragon."
https://www.gameteep.net/dragon-story/diamond-dragon/
Perhaps a new way to breed a diamond dragon? Island and firestorm? Anybody try this, but i have a concern as to where the purple comes into play unless the fire and water in the breeding provides the purple as well as the other 4 colors to ultimitely obtain the diamond dragon?
Worth a try right?