I think De'vID is referring to the fact that KGT claims Klingon has no noun for "color", and yet we've got one. It's an issue he's mentioned before.

My hypothesis: In the years since KGT was published, appreciation for Klingon art has increased among off-worlders, who wish to discuss art with the Klingon artists. However, Klingon artists have found that a lot of off-worlders, especially artists, use a noun for "color". To facilitate communication about the arts, Klingon artists have started using a noun for "color": qalmuS. Maybe it was an archaic word that was brought back into use, like the verb tlhogh. Or maybe it was originally an esoteric scientific word having to do with photon energies or something. Maybe it's a borrowing from another language. Only Maltz knows for sure.