Biological Machines/Appendix A
If light passes through a prism, a colour spectrum will be formed at the other end of the prism ranging from red to violet. The wavelength of the red light is from 650nm to 700nm, and the violet light is at around 400nm to 420nm. This is the EM range detectable for the human eye.
The colour triangle is often used to illustrate the colour-mixing effect. The triangle entangles the visible spectrum, and a white dot is located in the middle of the triangle. Because of additive colour mixing property of red (700nm), green(546nm) and blue(435nm), every colour can be produced by mixing those three colours.