While CMS adjustment is mainly thought of as adjusting the saturation, hue and brightness of each color to conform to the Rec. 709 (or whatever standard you’re using) color gamut, it should be noted that simply matching the points on the gamut triangle without paying attention to other factors can result in a lousy picture. When adjusting primary colors (Red, Blue, Green), the absolute luminance is of price concern. The Delta L (luminance error) should be minimized and the three colors should be close to each other in absolute luminance. For secondary colors (Cyan, Magenta, Yellow), it’s most important to get the hue correct. So, you’re looking for the hue error (Delta H) to be minimized. You can then try to get each color as close as you can to the individual points on the gamut, but without affecting the two goals stated above.