I agree with Marvin. Turquoise is on the green side of blue--aqua even more so. If your mixing paint pigments you simply add a little green to blue to get turquoise or aqua. Iris pigments are a different story. What works on a palette doesn't usually hold true for an iris.
For one thing the pigments are layered, so what lies in one layer affects how the eye sees the total color, sort of like colored filters on a lens. I think there is probably some yellow pigmentation underlying blue pigments in irises which present a turquoise coloration. If you examine the parentages of Daredevil and Condottiere, pink plays a part in both. Pink is a carotenoid pigment in irises, as is yellow, while blue is an anthocyanin. The turquoise effect may be due to an interplay between the two in different layers of the petals.
