For many years, there has been an intercontinental difference in the set of colors used on geologic mapssince 1881, in fact. In this image, the American standard is on the left and the International (European) standard is on the right. In some respects you could say that the difference is just an accident of history. But I wonder to what extent the colors represent real differences in geology. Even crazier, I wonder how much the differences represent differences in geologists. I have a notion, which I lay out in this new article, "Color in Geologic Maps: A Peculiar History." But I'm an American, raised on the American standard and little exposed to the other standard. I'd love to hear from geologists who have worked in both traditions. Was it a shock to encounter the other side? Were your synesthetic responses different? What color is the Triassic in your dreams?