These are very weak dyes and may have been used. IDK for sure. Anthrocyanines are also used but are weak and higher in molecular weight so you get less bang for the buck. Phthalocyanines or Merocyanines are often used. Look at Brooker's Merocyanine as an example. Leslie Brooker was the founder of the dye lab at EK and his work points directions for dye usage. Today, all dyes at EK are numbered using the Brooker system and so we have B-11774 and etc....

PE