Take a company that manufactures artist’s paints. They could sell hundreds of colors and most are made with the same “base” ingredients. Start adding the colorant, dye or pigment, and all of a sudden you have the potential for hundreds of unique ingredients and the potential for some differences.
What many folks do not understand is that each colorant, dye or pigment may have different hazards. The classification could change from paint to paint. It is imperative that each colorant, dye or pigment is researched to see if it meets any of the hazard criteria. Products may look the same once they are sitting on a shelf, but can be dramatically different in chemical composition. If something different occurs in the profile of hazards, then (M)SDS needs modified to be accordingly. We also strongly recommend a separate (M)SDS when the hazards are found to be different from the colors.
Add wanting to prepare an MSDS for Canada, the USA or Europe, and you have a variety of different disclosure criteria, cut-off values etc. Something that is regulated in one country may not be in another.