ancient greek words for colors
On the whole, the Greeks were not really concerned with giving names to specific colors. Their color terms were vague, often had more to do with shade than color difference, and drew in a sort of dynamic physicality that is honestly incredibly interesting.
μέλας and λευκός, which were commonly used to refer to black and white respectively, were still more involved with shade than the particular colors that we perceive as black and white. μέλας also meant dark, murky, and swarthy. λευκός was light, bright and clear, referred to any white color from a pure white to a light grey, and could also refer to someone with lighter skin.
χλωρός meant pale green or greenish yellow, but also commonly meant pale or pallid when referring to people and fresh or blooming when referring to plants and liquids (including blood and tears).
πορφύρεος is where we get the color term purple. And when it was referring to clothes or things, it did mean purple. But when it was describing people, especially their complexions, it meant bright red or flushed. This definition originates from the basic meaning of the word: heaving, surging, gushing, coming from the verb πορφύρω.
ξανθός and ἐρυθρός are perhaps the only straightforward terms, meaning yellow or golden and red respectively. ξανθός was typically used to describe blonde (ish) people; Achilles is described as having ξανθή κόμη (golden hair).
γλαυκός was commonly used to refer to the color grey, or simply to describe something as gleaming. When it refers to eyes, it usually describes the color; the most famous example being Athena and her epithet of γλαυκῶπις or grey-eyed (or gleaming eyed).
And now let's talk about κυάνεος. We get the color term cyan from it, and the word is popularly considered to refer to a dark blue. But that isn't exactly accurate. If we look at what this word typically described: hair, people, etc., it is clear that the concept of blue that we have nowadays wasn’t really coming into play. In fact, the more general translation is dark or black, conveying a shade rather than a color, like μέλας. If I were to attribute a color term to this word at all, I would probably say blue-black, or a cool black, to convey the depth of that shade, which is probably what the Greeks were describing.
A few more recent additions:
I just came across the adjective ἰοδνεφές in the Odyssey, which was describing the color of a sheep's wool, and literally it means dark as a violet flower, or purple dark, and I think it must be conveying a shade similar to κυάνεος.
πυρρός, meant flame colored and comes from the Greek word πῦρ fire. It could also be translated as a yellowish red color or tawny and was used to describe people with red hair.
ἰοειδής literally means looking like a violet, and is very similar to ἰοδνεφές above, as both originate from ἴον, violet flower.
πολιός is typically translated as grey, and usually describes the greying or grizzled appearance of an aged person's hair, but if you're reading the Odyssey, it is used to describe the color of the sea.
-nan