The perception of color is a complex biological and physical phenomenon that begins with light entering the human eye. Light is composed of different wavelengths, and our visual system interprets these wavelengths as distinct colors. The ultimate color we see depends entirely on whether we are dealing with light sources or physical substances that reflect light. The outcome of mixing color is not universal; it is governed by the specific method of combination, which determines whether wavelengths are being added together or selectively removed. Understanding this distinction is necessary to answer the question of what color the three primary elements make.
The Physics of Light Mixing
When red, green, and blue light are combined, they produce white light, following the principles of the additive color model. This result occurs because these three colors represent the primary colors of light, tied directly to the biology of human vision. Our eyes contain specialized photoreceptor cells called cones, which are maximally sensitive to red, green, and blue wavelengths. When separate beams of pure red, green, and blue light are projected onto the same spot, they stimulate all three cone types simultaneously and equally, which the brain interprets as white light. Mixing just two primary colors results in a secondary color, such as yellow (red and green), cyan (green and blue), or magenta (red and blue).
Pigment Mixing and Absorption
The process changes completely when mixing physical substances like paint or ink, which operate under the subtractive color model. If one were to mix traditional red, green, and blue pigments, the result would typically be a dark brown or black, not white. This difference arises because pigments do not emit light; instead, they create color by absorbing specific wavelengths of light and reflecting the rest back to the observer. Each pigment acts as a filter, removing its complementary color from the white light that shines upon it. When red, green, and blue pigments are mixed together, their combined action absorbs nearly all the light, leaving very little to be reflected, which the eye then perceives as black or a very dark shade.
How Screens Use Red Green and Blue
The additive color principle of red, green, and blue light is the foundation for all modern digital displays, including television screens, computer monitors, and smartphones. These devices create their spectrum of colors using a grid of microscopic light sources called pixels. Each individual pixel is composed of three smaller elements, known as subpixels, which emit red, green, and blue light. By controlling the intensity of the light emitted by each subpixel independently, a display can generate millions of different color variations. When all three subpixels are completely turned off, the pixel appears black; when they are all illuminated at maximum intensity, the combined light is perceived as white.