Colour Me Happy: A Quick and Simple Guide to Colour Systems

RGB, HEX, CMYK and PMS – sometimes it feels like designers are speaking a different language.

In my experience, colour systems is an area which can prompt lots of questions, so today’s post is all about demystifying things with a quick guide to the different colour systems you might hear your graphic or web designer talking about.


I suppose the short answer is because colour is complicated. When we take in a beautiful view or scene – a bed of wildflowers, a stormy sea, leaves on the turn from green to autumnal red – our eyes and brain perform incredibly sophisticated processes in microseconds in order to register those colours.

The different colour systems designers use – RGB, HEX, CMYK and PMS – are all, simply speaking, the means by which we attempt to match up the colours we see in the world with those we present on our website, our flyers or other materials. Each system is matched to a particular medium or format – just read on to find out more about each.


RGB stands for red, green and blue. These are the colours which light-emitting screens (i.e. your computer or phone) use or ‘mix’ to reproduce your desired colours.

Each colour has a value ranging from 0 to 255. An RGB value of 0, 0, 0 will give you black, whereas 255, 255, 255 will give you white. Everything else is somewhere in between. Remember learning about the colour wheel in primary school and mixing red, blue and yellow paints? This is similar, except we’re mixing light.



You could call HEX a sister language to RGB – there’s no intentional difference, but rather HEX and RGB are different ways of communicating the same red, green and blue colour equation.

HEX is commonly used for websites and in coding. Instead of 3-figure value as we see in RGB, however, a HEX value is a 6-figure code made up from numbers and letters. Make sure your designer lets you know your HEX codes just in case you need them for a web developer further down the line. Alternatively you can use online tools like to work it out.


This colour system is used when printing using ink, so whatever system you’ve used for your digital files it will need to be converted into CMYK if you’re printing on paper, card or anything else .

CMYK stands for cyan, magenta, yellow and key, the key plate being the plate which contains the details in the image. In CMYK, it’s usually done with black ink which is why some people (mistakenly) think ‘k’ stands for blac(k). And unlike RGB, the colours in CMYK are subtractive, meaning they get darker as you blend them together .

If you use lots of bright, vivid colours – and certainly if you rely on fluorescent or neon shades – you might find you struggle to produce these exactly in CMYK, which has a narrower range of colour than RGB. Also, neon shades rely on a light-emitting screen in order to be ‘true to life’, which isn’t an option when printing on paper and card – just a heads-up. This is when you have to use spot colours, also known as Pantone, which come ready mixed and are printed as a separate colour. Read on to find out more.


And last but not least we have PMS, which is used by designers and printers to ensure effective colour-matching. If you use a Pantone shade, it won’t matter if you get your T-shirts printed in Tottenham and your mugs printed in Milton Keynes – the colours should look the same on both.


There are over 1000 Pantone colours to choose from, including neons, pastels and metallics – although do be aware than using a Pantone or ‘spot colour can cost a little more. Usually printers have a five colour machine set up for CMYK plus a spot colour, so choosing Pantone means setting up a separate plate. However, lots of clients feel that paying a little more is worth it for the certainty of being able to reproduce their brand colours consistently wherever they go.

So there you have it: a whistle-stop tour of colour systems and which one it’s best to use when. If you have any questions about them – or anything else branding-related – don’t hesitate to drop me a line via my contact page or on email via