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Home Cosmetic Science Talk Formulating Color and makeup Color-Changing D&C Red No. 21 and 27

  • Color-Changing D&C Red No. 21 and 27

    Posted by hubahubister on January 30, 2021 at 5:13 am

    Hi All
    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.
    Thanks
    Noni

    MelindaNicole replied 2 months ago 2 Members · 1 Reply
  • 1 Reply
  • MelindaNicole

    Member
    March 28, 2023 at 10:35 pm

    The pH color changing is due to bromo acid powder dye that is water insoluble. I bought a couple this past summer but haven’t had a chance to play with them yet.