Monitors, televisions, and other digital devices generally use the RGB color model. It refers to red, green, and blue – the three colors of light which, when combined,  create the spectrum of colors on your screen.  When none are present, our monitor is black, when all mix, we get white. For print applications, the CMYK is color system is used.

The acronyms above reference color models used by design professionals. RGB is generally used on screen while the other two describe print color m0dels (see more at this link).   In the above sketch, when viewed on a screen, the red feels the truest in the  RGB model.