For some reason, anytime I try to paint a dark color on top of a lighter one, the edges of my brush appear dessaturated and grayish. The center is the true color but the outside edge isn't. I have opacity set to pen pressure. Opacity and Flow are at 100%. There are no filters on and the color chosen is the most saturated possible. My monitor settings are right so I think it's something to do with photoshop. The only settings on the brush are opacity jitter and smoothing. Please help, I can't paint with true colors!