What is RGB? How is it used? What about RGB lighting?

If you have ever used a gaming computer, a TV, or a camera, it is impossible for you not to have met with the term RGB. Do you want to know what RGB stands for, what it's used for, or why you hear so often about RGB when computers, gadgets, or displays are involved? We are here to make this all a bit clearer so, if you want to find out what RGB is, which are the most common ways in which it is used, and why, read this article:

What does RGB stand for?

RGB is an acronym for "Red Green Blue," and, as you have guessed, it refers to colors and how colors are composed. Why red, green, and blue, you might ask? The answer is that red, green, and blue are the primary colors that you can combine in various amounts to obtain any other color from the visible spectrum that the human eye can see.

RGB is an additive color model. In other words, to obtain other colors, you mix the primary red, green, and blue colors. If you mix all three colors at their maximum intensity (100%), you get white. On the other hand, if you mix all of them at their minimum intensity (0%), you get black.

The RGB color model

In other words, mixing equal parts of 100% red, green, and blue, you get light, and if you mix 0% of red, green, and blue, you get darkness.

RGB can also be considered as the opposite of CMY, which stands for "Cyan Magenta Yellow." Why the opposite? Because CMY as a color model, is the antithesis of RGB: combining cyan, magenta, and yellow at 100% maximum intensity gives you black, while 0% minimum intensity gives you white.

The CMY color model

Ways in which RGB is used

First of all, the RGB color model is used in devices that use color. Due to the fact that it is an additive color model that outputs lighter colors when the three primary mixed colors (red, green, blue) are more saturated, RGB is best suited for emissive image display. In other words, the RGB color model is best suited for illuminated screens, such as TVs, computer displays, laptop displays, smartphone and tablet screens.

In comparison, CMYK, which stands for "Cyan Magenta Yellow Key (Black)" and derives from CMY, is a reflective color model, meaning that its colors are reflected rather than illuminated, and is used mainly in print. That's why, when calibrating a printer, you work with the CMY color space while, when calibrating a computer display, you work with RGB.

Printers are using the CMYK color model

Besides TVs and other electronic displays, the RGB color model is also used in other devices that work with illuminated colors, such as photo and video cameras, or scanners.

For example, LCD screens are made of many pixels that form their surface. Each of those pixels is usually made of three different light sources, and each of them can turn red, green, or blue. If you look closely at an LCD screen, using a magnifying glass, you can see these small light sources that form pixels. However, when you are looking at it like a normal person would, without a magnifying glass, you only see the colors emitted by those tiny light sources in the pixels. By combining red, green, and blue, and by adjusting their luminance, the pixels can make any color.

RGB light sources of the pixels on a screen

RGB is also the most widely used color model in software. To be able to specify a certain color, the RGB color model is described by three numbers, each of the numbers representing the intensity of red, green, and blue colors. However, the ranges of the three numbers can differ depending on what reference you use. Standard RGB notations can use triplets of values from 0 to 255, some can use arithmetic values from 0.0 to 1.0, and some can use percentage values from 0% to 100%.

For instance, if the RGB colors are represented by 8 bits each, it would mean that the range of each color can go from 0 to 255, 0 being the lowest intensity of a color and 255 the highest one. Using this notation system, RGB (0, 0, 0) would mean black and RGB (255, 255, 255) would mean white. Also, the purest red would be RGB (255, 0, 0), purest green would be RGB (0, 255, 0), and the purest blue would be RGB (0, 0, 255).

Representing RGB colors in an 8-bit notation, each color with a range from 0 to 255

We did not choose this example by chance: RGB is often represented in software by an 8-bit per channel notation. If you're wondering why 255 is the maximum value in the 8-bit notation, that's because each color in it is represented by 8 bits. A bit can have two values: 0 or 1. Raise 2 (the number of values of a bit) to the power of 8 (the number of bits assigned for each color) and you get 256, which is the exact number of numbers from 0 to 255. Geeky, right? :)

However, other notations are also commonly used, such as 16-bit per channel or 24-bit per channel notations. In 16-bit for example, the range of values for each of the RGB colors goes from 0 to 65535, while in the 24-bit notation, they go from 0 to 16777215. The 24-bit notation covers 16 million colors, which is more than all the colors that are visible to the human eye, which tops at about 10 million.

Welcome to the rainbow of RGB lighting

From software to hardware, RGB is all over, and one of the most trendy ways of using RGB in the modern world is RGB lighting. We're talking about using RGB LEDs to light up not just our screens, but the backs of our monitors, TVs, gaming accessories such as keyboards and mice, motherboards, graphics cards, PC cases, processor coolers, fans, and even gaming chairs!

RGB lighting has pushed its way into a huge array of devices and even into some furniture. Although some people think it's pretty silly, others think that it's cool. Whether you like rainbows or prefer to light up everything in a single color, RGB lets you do it.

An RGB lit gaming computer built with ASUS hardware

But how does RGB lighting work? The answer is simpler than you might think, and it all relates to what RGB means: Red Green Blue. Essentially, all RGB lit devices and fixtures have strips or bundles of RGB LEDs. An RGB LED is a mix of three differently colored LEDs put together: one Red LED, one Green LED, and one Blue LED.

A closeup of a RGB LED taken from Wikipedia

Image source: Wikipedia

By combining the three LEDs, mixing their color intensity and luminance, you can obtain almost any color you want. That is, if you are not looking at the LEDs too close.

Maybe the best implementation of RGB lighting is the one we see increasingly more often in gaming computers. One of the best things about it is that you can use software to customize and adapt your computer's RGB lighting effects as you wish. Such an example is ASUS' Aura software, which lets you sync the RGB lighting effects and even have special in-game effects that adjust on-the-fly depending on the actions in your game.

ASUS Aura RGB lighting effects and settings

Either way, once you have gone the RGB way, you'll probably love it, thanks to the amount of personalization you get.

Do you have other questions regarding RGB?

This was just a brief explanation of what RGB is and what it is used for. It is a complex subject with complex ramifications in many technologies and industries, both related to hardware and software. Thus, we are pretty sure that you might have some additional questions about RGB so, if you do, ask away in the comments section below and we promise to do our best to help you figure out the answers.