Butterfly Pea Flower Tea and Natural Blue Pigments

https://blue-blossom-brew.keystonescope.com/posts/tea-gift-sets-for-parents-who-love-a-daily-cup

Butterfly Pea Flower Tea and Natural Blue Pigments Butterfly pea flowers contain color pigments called anthocyanins. Their hue changes with acidity, so the effect is chemistry rather than artificial dye