TV screens only have tiny dots, each dot is some shade of red, green, or blue. How can the other colors be seen? Explain by using the color yellow.
Although TV screens only have tiny dots that emit red, green, and blue light, the perception of other colors, such as yellow, is possible through a phenomenon known as additive color mixing.
When red, green, and blue lights are combined at varying intensities, they stimulate the three types of color receptors, or cones, present in our eyes. These cones are sensitive to different wavelengths of light, with short-wavelength cones primarily responding to blue light, medium-wavelength cones to green light, and long-wavelength cones to red light.
Yellow is perceived when our medium-wavelength (green) and long-wavelength (red) cones are stimulated simultaneously, with less stimulation of the short-wavelength (blue) cones. To create the perception of yellow on a TV screen, the tiny dots that emit red and green light are turned on simultaneously at different intensities, while the blue dots remain off.
For example, if the red and green dots are turned on fully while the blue dots remain off, the combination of these two primary colors results in the perception of yellow. Similarly, reducing the intensity of the red or green dots while keeping the other at maximum intensity can create different shades of yellow, ranging from pale yellow to vibrant yellow.
By manipulating the intensity and proportion of red, green, and blue light emitting from the tiny dots on the TV screen, various other colors can be perceived, including all secondary colors (like purple, orange, and green) and their intermediate shades. This additive color mixing principle forms the basis for the vibrant and diverse color range that can be displayed on TV screens.