After doing a little online research, it appears that the pigment delphinidin does occur in irises and in fact in all blue flowers and is responsible for all shades of blue, not just turquoise. The blueness of its expression is evidently controlled by many other factors like chelates, which are beyond the scope of my expertise and would probably require someone with a background in chemistry to adequately understand. Sorry. My training is basically in art and languages. Also, apparently carotenoid and anthocyanin pigments, while they do not mix on a molecular level, do evidently occur in pockets in the same layer. There are some interesting articles on the internet about iris pigmentation for those who are intellectually able to digest them. I am not one of them.
