Anthoxanthin

Anthoxanthins are a type of flavonoid pigments in plants. Anthoxanthins are water-soluble pigments which range in color from a white or colorless to a creamy to a yellow, often on petals of flowers. These pigments are generally whiter in an acid medium and yellowed in an alkaline medium.

They are very susceptible to color changes with minerals and metal ions, similar to anthocyanins. Some examples of anthoxanthins include: apigeniun, luteolin, kaempferol, quercetin.

Source: https://en.wikipedia.org/wiki/Anthoxanthin