Here is the RCW, YMC and also the RGB tint color wheel, reduced to a gray scale.
Below is the computer RGB shade color wheel and it's gray scale image.
Red, green and most of blue are the same gray scale tone.
Below is the Real Color Wheel (RCW) with the yellow being a warm brown before black,
and cyan shades to Ultramarine Blue before going black.
This changes the RGB/YMC color wheel into a Real Color Wheel for pigment artists.
RCW has the more even grayscale scale values also.
Here is a gray-scale chart.
