The myth about the Ancient Greeks and Romans not distinguishing various colors has arisen in the 19th century, because those who knew well enough Ancient Greek or Latin to be able to read the ancient literature were ignorant in chemistry, mineralogy and biology, so they were not able to recognize the chemical substances, minerals, plants or animals described in the ancient literature, so they were unable to recognize which were their colors.
Ancient Greek and Latin and also most old languages had very few words that were just color names. Most colors were referred to as "the color of X", where "X" was some well known colored thing. Even for the very few words that were just color names, like "red", a phrase like "the color of X" was preferred for naming precise hues. For instance, "red" could mean either pure red or purple, so when precision was needed the former was referred as "the color of coccos", while the latter was referred as "the color of purple", where "coccos" was a red dye extracted from certain beetles and "purple" was the purple dye extracted from marine snails.
When those reading the ancient literature could not identify "X", they could not identify the color that was named there. At the end, after ignoring most colors mentioned in a text, their (wrong ) conclusion was that the text did not contain color references, except perhaps to red, white, black or gray.
So it is not a fact that the Ancients did not discuss about many colors, but the modern scholars with a not wide enough knowledge were those who could not understand the ancient phrases used to name colors like blue, blue-green, green, brown and others.
But consider in English we currently do this blue and light blue. Where say Spanish calls them different colours - blue and celeste, and they are linguistically seen as different named colours.
Interestingly we don't do this with red, there's no red and light red, but red and pink.