The legend on wikicommons says that red countries are countries that used to use a dollar currency. I see how having Spain there could cause confusion, so I'll edit the hint so that it points more to the countries in green, thank you!
I had absolutely no idea what the light-eyed map was but that is extremely interesting. I nominated the first one and I would with this but I don't want to make a habit of using my nominations haha. Awesome quiz though I love it! Definitely one of my favorite quizzes on this site.