Why does red and blue pigment make purple?
I’ll start out with a disclaimer. I am not an artist. I understand that mixing red and blue pigment (or paint) does not produce a true purple. I’d like to talk about the science behind what is happening in our eyes when we perceive color. I’ll leave discussion of the color wheel, the true primary colors and what color is produced when red and blue paint are mixed to the artists! It’s important to talk about the difference in how colors are produced by pigments and how color is produced by light. Let’s start out with light. The visible spectrum of light goes from a wavelength of 400 nanometers (nm) to 700 nm. I remember learning the acronym ROYGBiV (Red Orange Yellow Green Blue Violet) in school to remember the sequence of colors in the visible spectrum. Red light has the longest wavelengths (from about 575-700nm) and the lowest amount of energy. Violet light has shorter wavelengths (about 400-435 nm) and much greater energy....