I have a 1971 Gitane Apache that I'm working on and having the same problems with paint colour. Mine is a weird combo of burnt orange and goldy tan fused together? near impossible to match the paint. I did a google search on cars that were (insert colour here), then took the make and year and went to a car paint touch up store to see what they offered. It's still a crap shoot though and those touch up applicators aren't cheap.

How do body shops match a cars paint so well? Is there some method they have to match the exact colour (which is the easy part, I have an app on my phone that does that) and then have the paint custom made? I would guess that would be costly as well.