Re: can't get green tone in gum--help please
I think the discussion of this problem left some murk -- because the colors advised and mentioned were all by generic color name only, which presses the button to which I respond:
Just saying "ultramarine" or "hansa yellow" or some other color may well be meaningless... since each company names its colors at will and mixes them likewise, that is, with its own additives, sources, pigments, and other fixed ideas, which as a rule make paints with the same *name* perform very differently in a sensitive medium like gum.
The numbers given (by I forget which authority) to the various colors can help, but IME even the same "numbers" from different makers vary in practice (not to mention from lot to lot -- for instance a black I'd used in mixes for YEARS, when that tube ran out, was replaced with something useless by same name, same company).
Indeed, the fellow seeking that particular green may have been too kosher -- that is, it's nearly always possible (again IME) to mix just exactly the color you want from paint and gum with some acrylic medium of the proper gloss, then gently lay it on, plus touch ups with paint, colored pencil, etc. as needed.