This is actually debated too. The use of 'wine-dark sea' in the Iliad and the Odyssey has caused a lot of debate over linguistic relativity in regard to colours, and the most common conclusion is that the Ancient Greeks didn't differentiate between dark blue and dark red. In fact, if you look back you find a lot of languages just don't have a word for blue at all. Elsewhere in Greek writing you have chlooros, which is variably used to describe the colour of honey, olive bark, a horse, sand, a scared person's face, and a plague victim's skin. One theory I've seen that might solve this is that the Ancient Greek conception of colour was primarily about its shade rather than its hue, so things would be described as pale or dark rather than as red or blue or green or yellow. Does that mean that Ancient Greek people would actually interpret the world differently as a result? Does thought shape language, or language thought, or both at the same time? It's a tough topic to wrap your mind around, but I suppose it always is when the mind starts to contemplate itself. Please open this box with the crowbar inside the box.
(A more clearly culturally-rooted example is the opening line of the novel Neuromancer: 'the sky above the port was the color of television, tuned to a dead channel'. Originally it meant static, nowadays many would think it means a clear blue. How long until it doesn't make any sense at all?)
Purple is more reddish according to my research. And by research I mean wikipedia diving about a month ago.
