And from
Wikipedia I found there is Additive coloring and Subtractive coloring,
Additive coloringAdditive color is light created by mixing together light of two or more different colors. Red, green, and blue are the additive primary colors normally used in additive color systems such as projectors and computer terminals.
Additive color mixing: combining red and green yields yellow; combining all three primary colors together yields white.
Subtractive coloringSubtractive coloring uses dyes, inks, pigments, or filters to absorb some wavelengths of light and not others. The color that a surface displays comes from the parts of the visible spectrum that are not absorbed and therefore remain visible. Without pigments or dye, fabric fibers, paint base and paper are usually made of particles that scatter white light (all colors) well in all directions. When a pigment or ink is added, wavelengths are absorbed or "subtracted" from white light, so light of another color reaches the eye.
If the light is not a pure white source (the case of nearly all forms of artificial lighting), the resulting spectrum will appear a slightly different color. Red paint, viewed under blue light, may appear black. Red paint is red because it scatters only the red components of the spectrum. If red paint is illuminated by blue light, it will be absorbed by the red paint, creating the appearance of a black object.
Subtractive color mixing: combining yellow and magenta yields red; combining all three primary colors together yields black
Now when you teach the primary colors in school explain this as well to you students, Thanks.
(you can read
here more about rgb on screen)
And more hereComparison of RGB and RYB color wheels
Unlike the RGB (CMY) color wheel, the RYB color wheel has no scientific basis. The RYB color wheel was invented centuries before the 1890s, when it was found by experiment that magenta, yellow, and cyan are the primary colors of pigment, not red, yellow, and blue.
The RGB (CMY) color wheel has largely replaced the traditional RYB color wheel because it is possible to display much brighter and more saturated colors using the primary and secondary colors of the RGB (CMY) color wheel. In the terminology of color theory, RGB color space (CMY color space) has a much larger color gamut than RYB color space.