I was experimenting with Krita, and LAB color space, and I realize how powerful is LAB is as a color space. I can do color-correct inversion, I can shift colors and the color shift is perceptually correct. I can add warm/cool color using LAB color, and so on. I can do just about anything in LAB without the burden of HSV! I can stimulate color-blindess! I can use a LAB Krita file as a background file, and keep it with complimentary color, and then put it as a file layer in a RGB document, and then shift hue with it. Praise LAB!