Regular Matrix film was yellow. It used Tartrazine alone.

As a side note, Pan Matrix film was black and used a soluble dye. Some claim that carbon was used to form the black and it remained. Well, here is the extended story as far as I can figure out. The early Pan Matrix was black and the dye washed out. This was so Pan Matrix and Matrix images were identical and could be compared. It allowed for easy reading of the gray scale that was included. Also, Carbon Black was made from burning tallow which imparted some harmful organics to the carbon mix. So, it was not used. In later years, pure Carbon Black was made available primarily for the image transfer products, and this was used as a permanent black image in Pan Matrix film along with the silver image.