If I were the author I would train another NN that compares the color with a huge set of photo+definition and decide from there. For instance "Coral Gray" looks

If I were the author I would train another NN that compares the color with a huge set of photo+definition and decide from there. For instance "Coral Gray" looks quite accurate when compared with the average recreational diver photo of coral reefs (but not the real coral specimens, which tend to be very colorful when correctly photographed).