cmyk or rgb Colour Process

CMYK or RGB: A Beginners Guide to Colour Process

Colour is an important part of any design job, be it web design, print design, branding or any of the other numerous disciplines that make up a designer’s day to day work. It can affect mood and evoke emotions. Think of a Mercedes car, chances are you are thinking of a silver one, going to show that colour can become a brand in itself. So, when it comes to print design you need to make sure the colours are correct and that you are using the correct processes, which we will explore in this short blog post.

Open Photoshop, Illustrator or any other design based software and you will be greeted with a colour process choice. CMYK or RGB. Each program has its defaults, the image editing purpose of Photoshop defaults RGB whilst the layout tool InDesign defaults to CMYK. What’s the difference and which one should you choose? Let’s look at what each process covers, starting with RGB.


RGB is called RGB because of the colours that are involved in it’s make up. R – Red, G – Green, B – Blue. Simple. These three colours are also what makes up your electronic device screens. From phones to TV’s, RGB is at the heart of it all.

RGB is an additive colour system which means that the primary colours are added together in various combinations to produce a much wider spectrum of colours. These colours are produced by blending light itself by superimposing the red, green, and blue light beam. Without any intensity, each of those colours will be perceived as black, while full intensity will make them appear white.

So, when would you use RGB in design? Basically, any time you are working on a digital project. Websites, social media imagery etc. If you use RGB on print, the colours will need to be converted. We’ll discuss more on that later.


The other common process is CMYK. If you work in an environment where a printer is present, you will have probably come across these colours when ordering new ink. CMYK stands for C – Cyan, M – Magento, Y – Yellow and K – Black (K actually stands for ‘Key’ which is also known as Black).

CMYK works in an entirely different way to RGB as instead of using ‘additive’ types of colour, it uses subtractive colours.

The main difference is this; when you combine all the colours of the RGB colour mode (red, green and blue) in varying amounts, you end up with the colour white (i.e. the purest combination). With the CMYK colour mode, all the colours are subtractive and therefore, the more colours you add together, the darker the colours are going to be.

If you use RGB for digital, you can already work out what CMYK is used for… Print! Magazines, Billboards, Business Cards are all printed in CMYK in a professional environment.

A common mistake is to open Photoshop to design a flyer and not think about colour. As Photoshop is an editor that is used for a lot of image and web work, it defaults to RGB, so whenever you open a program double check it is set up for the correct use.

I mentioned before that converting from RGB to CMYK is possible and yes, converting the colour by just a couple of clicks sounds like a good idea, however caution must be taken. Converting from RGB to CMYK for print like this can wash out your colours. What you thought was purple now appears more blue. Same can be said about greens, printing makes them appear flat and dull.

The best advice I can give is stop and take a minute to think about what the job entails. Will it be going on Facebook? RGB. Newspaper? CMYK. Setting up the correct colours can save headaches further down the line. You don’t want a brochure for your favourite sports team in their red kit to be printed a muddy brown colour do you!

That just scratches the surface of colour theory within design. If you want to ensure your brand shines in any colour, we are always on hand to help. Just give us a call on 01302 613 000.

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