You may want to try the colour lookup table (not the ‘LUT 3D’) module. It allows you to pick colours, and then change lightness, green/red, blue/yellow ratios and saturation. This can also be done with colour zones, but maybe the colour lookup table is simpler (in colour zones, you have to pick 3 times, as each of the tabs (lightness, saturation, hue) allow / require distinct selections).