Which compound or compounds are responsible for color change in blue butterfly pea flower tea? Blue Butterfly Pea flower tea is blue by default. Add citrus juice and it turns purple. What compound or compounds are responsible for this reaction to change in pH?

Wikipedia doesn't say, nor can I find any source on the internet that does.
OK, that was simple. This

https://www.google.de/search?q=Clitoria+Ternatea+blue+color

gave this

https://www.ncbi.nlm.nih.gov/pubmed/14568080 

which lead me to this

https://en.wikipedia.org/wiki/Anthocyanidin

and I guess that's the culprit. I judge from that abstract linked above that the actual plant can contain a wide mixture of those anthocyanidines.