Color Filter is a thin layer to represent colors in LCDs. When the light from the backlight unit passes through liquid crystal and finally passes through a color filter composed of Red, Green, and Blue, the color of the light is changed according to which color filter it passed. It’s similar to light changing its color depending on the color of the cellophane when you expose a flashlight on cellophane.

What if there’s no color filter in LCDs? It would be expressed by bright and dark gradations, like black and white TV. Most displays utilize a combination of three primary colors of light, Red(R), Green(G), and Blue(B), to represent various colors. Typically, one pixel has three sub-pixels of each color - R, G, and B – and more than a million colors can be reproduced through various combinations.