I'd like to be able to mark a range in the histogram and see the map get colored around that range. In other words: Currently -100% to +10000000000% is colored red-to-white-to-green. I want to be able to mark -20% to +200% such that * -20% and below turns red * -20% to +200% turns gradient red-to-white-to-green * the rest turns green The current coloring is very much indistinguishable in the green area as is.