Color-Changing D&C Red No. 21 and 27
I am trying to identify which group/class of this (color-changing) dye D&C Red No. 21 and 27 ( CI45380:2 and CI45410:1 respectively).
They are solvent dye. To narrow it down further, are they an acid dye or basic dye?
Appreciate if anyone with more experience can help clarify this.