Don't worry about overdoing the paprika. Beta carotenes are only sparsely turned into vitamin A, and this is done in the gut. Unlike the straight vitamin A from fat and liver or vitamin powders, which are almost totally utilized and stored even to a toxic level in the liver with overdoses, there is a feed back mechanism that prevents the metabolism of carotenes into vitamin A unless it is needed. Some of the excess carotenes, which are fat soluble may absorbed and stored in the lipids of fat cells just under the dermis and somewhat in the dermal lipids, enhancing the yellows and reds.
What would enhance blue, would be an interesting study, but I haven't found any research on it yet. The spirulina would certainly be safe enough to try.
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Patty
Lost River, Idaho
4 D. auratus blue
3 D. galactonotus pumpkin orange splash back
5 D. imitator
4 D. leukomelas
4 D. pumilio Bastimentos