Natural + GRAS source of blue pigment?

[geraldmarken]

I'm working on a product that I would like to be vibrant green (not absinthe, for the record, but this seems like the most appropriate place to discuss it). As has been discussed elsewhere, a stable green is hard to obtain as it normally turns brownish in a short period of time. This is not necessarily the case with blue and yellow pigments, however. What I'd like to do is use saffron and cornflowers or butterfly pea flowers as a way to get green. The problem is that neither of the blue flowers are GRAS.

Does anyone know of a natural + GRAS source of blue pigment?

On a separate note, which I'm also posting elsewhere as a new topic, is there a way to use non-GRAS ingredients that have a history of use? There seems to be a nebulous loophole...

Quote

Can the use of a substance be GRAS even if it is not listed by FDA? Yes…The use of a substance is GRAS because of widespread knowledge among the community of qualified experts, not because of a listing or other administrative activity.”

What's up with this?^^

[RobertS]

Generally Regarded As Safe means exactly what it says. It does not require official testing, just that traditional lore has okayed it. There is a central GRAS list that acts as a FAQ; if you are using something there you're good to go. If it's not on the list, you need to do what you're doing and make a case that it is GRAS.

EDIT: Google poking says try red cabbage?

[Cultus Bay Distillery]

Interesting. The initial red color of red cabbage does indeed degrade to a bluish color as time and (if I recall) pH change.

[RobertS]

Can't comment on its stability, which may bring us back to the original problem. On the other hand and off topic, a pH indicator coloring agent could be an interesting toy for mixologists.

[bluestar]

Violets are blue (although roses aren't quite red), but you will get the flavor with that too, and it is very distinctive.