I would also note that they may have mixed different varieties of grapes, used different materials for containers, mixed water and anything else they felt like

I would also note that they may have mixed different varieties of grapes, used different materials for containers, mixed water and anything else they felt like mixing in with it, and stored their wine in different conditions than are common today. It probably wasn't very well strained either, compared to today's wine. If you look at "natural wines" available now you'll see they are all kinds of colors. If you look at the sea in different circumstances it will be different colors. I suspect the reason this becomes a problem for modern readers is that we became used to drinking unadulterated wines from crystal clear glasses. My guess is that to an ancient Greek, the color of wine was less a fixed point and more of a spectrum.