What are ScB, ScG and ScR values?

I'm learning to make CC, so I sometimes open other creators' work in S4Studio to see what they did/use it kind of as a template while learning. I opened this custom skin tone CC and it opened straight into the warehouse. When I clicked one of the swatches, the Data field has "SwatchColors - Edit Items", but clicking "edit items" allows you to input ScB, ScG and ScR values instead of the normal RGB values to change the color of the swatch.
 mobdro kodi


I can't figure out how to use that. I can't figure out how to get the Sc values of a color in any program I can find. How do you do that?