Colour Name Confusion

[imbrius]

I'm slightly confused by some colour names I've seen for non-tartan items, specifically hose, waistcoats, and jackets.

I've seen modern red, tartan red, burgundy, and claret; modern blue, ancient blue, lovat blue, and navy; hunting green, lovat green, and ancient green. I've seen bison, fawn, oatmeal, and grey.

Which of these are just different names for the same colours and which are actually colours? This happened because a fellow kilt-wearer noted that one of my tweed jackets was an "ancient blue", not a "lovat blue" as I'd been saying based on the advert from which I bought it. To complicate things, my wife, an art historian, noted that it was not blue at all, but a "tint of slate".