Understanding RGB

Watching Arvid Schneider’s tutorials I realised pretty quickly that he works a lot with RGB channels and uses different maps in these. Gerald Bakker had an incredibly useful article on the use of RGB channels, taking me back to the basics, so I thought this would be a safe place to start.

Colour coding- digital colours are numbered, this is the only way that a computer can store a colour. A computer can’t process colour as humans do- as a property of light/mixture of wavelengths, so they need these numbers to be able to store, process and show an image.

The smallest form of an image is pixels- and each of these pixels contains one colour- but how does these internally- let’s find out!

RGB coding

RGB stands for Red, Green and Blue, it gives the assumption that every colour is made up with variations of RGB. If you look at a colour wheel in photoshop, each RGB can work from 0-255. 0 being nothing, 255 meaning the absolute amount.

When changing RGB levels there are several observations to make

First observation: In the RGB way of color coding, the higher the numbers, the lighter the corresponding color.

 Second observation: When all three of R, G and B are equal, we get a neutral color: white, grey or black.

Third observation: When the three RGB values are close to each other, the corresponding color is close to neutral. The more they differ, the stronger, purer the color.

This mixing of the colours in their maximum amounts gives the following;


Fig.1, The mixing of maximums.

The names of the colours where they overlap are yellow, cyan and magenta.

Fourth observation: When increasing one component in any RGB combination, the color will go more towards that component and become lighter, both at the same time. Similarly, remove some of one component and the color will move away form it and get darker.

Fifth observation: The closer to white or black, the less pure a color can be coded in RGB. No RGB-coded color is “very light” (or “very dark”) and “highly saturated” at the same time. Keep making any color lighter, and it will become white eventually.

This article talked about the use of RGB masks, something I’ll have to look into for my shading set up for final year.


My friend Christain very kindly went into some depth with texturing today for me, as I was struggling to find answers to questions I had on Arvid Schneider’s tutorials.

Question- why do most maps appear to connect to the ‘R’ channel

He explained that if you want to use a floating value, then you connect it to the R channel, as it counteracts the need to use 3 maps as opposed to one, Eureka!