How does color on a computer screen work? I always thought that color was a way that light reflects on different materials/objects. How does this work on a TV/computer screen?
In: Technology
Color is just a specific wavelength of light hitting your retina. For example, a light wave with a wavelength of 530nm will appear to look “green” to you.
Most objects are *reflective*, in that they absorb some wavelengths of light and reflect others – the wavelengths they reflect are the colors you see. When the sun shines, the tree leaves look green because they absorb all wavelengths except for green, which is reflected back to you.
Other objects are emissive, in that they give off light waves. The color of light they emit will correspond to the wavelength of those waves. Older incandescent lightbulbs generally emit a yellowish-white light, which means that they emit all wavelengths but most of it in higher wavelengths, towards the red/infared portion of the visible spectrum.
With white light like this, you can filter out certain light waves with some translucent material. For example, you can make a flashlight shine red if you shine it through a red piece of glass. This red piece of glass filters out all the other wavelengths, leaving only red light to shine through.
Your computer uses LEDs in a similar fashion to light up pixels using 3 different colors. Each pixel can emit Red, Green, and Blue light, and it uses a combination of these colors to make up the image you see on the screen.
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