The reason why this phenomenon occurs is because rules in mixing paints, inks, and dyes are not the same as those in mixing light. When a painter looks at their palette they can create any color with the three primary pigments: magenta, cyan, and yellow. It is not the same for a projection television. Colors such red, blue and green (called primary colors) are used to create all of the colors.
When the three primary colors of light are mixed, the intensities of the colored light are added. An example of this is where primary color light overlaps. When red light is added to green light, yellow light is formed. All colors can be made by the addition of different lights of the three primary colors. For example, red is 100% of red light and red light only. Blended colors like orange are 1 part green and 2 parts red light. Some color mixing is very complicated, like for instances gray is 3 parts red, 3 parts green and 1 part blue. The equal mixture of all three primary colors forms white light.
Our eyes are like television, in that they mix the primary colors of light to form an image. The human eye consists of two types of light receptors, rods and cones. Rods are used for light at low levels, like when you are in the dark. Rods in your eyes tell your brain to see things in black and white, so they perceive how much dim or intense the image is. Cones are what we use to see color. There are three types of cones: cones sensitive to red, blue and green. Based on how much each type of cone is stimulated due to the specific light, we perceive the color of light. For example if both red and green cones are stimulated, then we perceive yellow light. If only green cones are stimulated, we perceive it as green light. These three types of cones generate color vision.
Whereas primary colors are mixed in an additive manner, primary pigments are mixed in a subtractive manner. The primary pigments for mixing dyes used in coloring, photography, and printing are: magenta (light purplish pink), cyan (light blue) and yellow. The dyes of inks absorb certain colors. Any color that is not absorbed (subtracted) is the hue that we see. These dyes act as filters that subtract one or more colors. By varying the proportion of the colors in a mixture, a full range of colors can be produced. For example, the color yellow absorbs blue and reflects red and green. Magenta absorbs green and reflects red and blue. So, the mixture of yellow and magenta equals red (white minus blue minus green equals red). The mixture of all primary pigments is black, all light being absorbed.In printing, the primary pigments are layered. A white layer is laid down first, followed by a yellow, magenta and cyan layer. Each pigment layer is carefully laid out to create a final image with the desired colors