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Cue words in paint labelling that indicate the pigment is a convenience mix, or otherwise adulterated are: "Hue" "Extra" and apparently "Lake" as well.
The insatiably curious among us will have to master organic chemistry in order to navigate the list of synthetic pigments . Perhaps ASTM has "upgraded" PR-83 from anthraquinone to add the "dihydroxy" prefixes? I dunno what that means to the designation which has been common since 1870, other than the "anthra" indicates that coal-tar (anthracite) is still the raw material. Claiming light-fastness of "I" indicates a change for the better.
Tom, as painting mediums entail different oils, resins and solvents, mixing paints mulled in walnut oil with those mulled in linseed is not a problem. W&N uses safflower/linseed blended oil in some of their colors. Oils of different specific gravities will ultimately separate in fluid state, this may not happen when the blend is mulled into paint, but why compromise linseed with an inferior oil?
David, Madder Root never was the raw material in Alizarine colors. At one time, "Madder Lake" meant something "real", as the colorant (dye) extracted from madder root was used to make a "lake", i.e., dye an inert solid which could be mulled into paint. There were other processes, but Rose Madder was always considered a fugitive color.
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