There are a lot of acronyms around for colour profiles – CMYK, RGB, HEX, PMS – But what do they all mean? Different colour profiles are suitable for different applications. The most important thing to consider is whether the design will be used for a digital or print application. If it’s a design to be used digitally (e.g. a social media post/website/video) then you will want to use RGB/HEX colour profiles. Whereas if it’s a design to be used for print (e.g. business cards/brochures/posters) then you will want to use CMYK/PMS colour profiles. Find out more about each of the profiles below:
RGB is the most common colour profile for digital use and simply stands for ‘Red, Green, Blue’. The red, green and blue primary colours of light are added together in various amounts to create a broad range of colours. RGB colours are formed of three values – The first being the value for red, the second being the value for green and the third being the value for blue. Each value will range between 0 and 255.
Black is [0,0,0], White is [255, 255, 255] and Grey is any [x,x,x] where all the numbers are the same. Bright red would be [255, 0, 0], bright green would be [0, 255, 0] and bright blue would be [0, 0, 255].
RGB is known as an ‘additive’ colour profile, because you add the primary colours of light together to create new colours:
Green and Blue light combine to make Cyan
Blue and Red light combine to make Magenta
Red and Green light combine to make Yellow
Red, Green, and Blue light combine to make White
The key thing to remember about RGB colours is that they can only be used by devices that generate light. Printed materials don’t generate light, they can only reflect the light that hits them. Therefore, they need to use a different colour profile based on reflecting light instead of producing it – This is how CMYK works, which you can read more on below.
Hex stands for Hexadecimal and is basically a short code to represent an RGB value. It is made up of a # followed by a combination of six numbers and letters. The first two numbers represent red, the middle two represent green, and the last two represent blue.
Black is #000000, White is #FFFFFF and Grey is any #XXXXXX where all the numbers/letters are the same. Bright red would be #FF0000, bright green would be #00FF00 and bright blue would be #0000FF. So you’ll notice it works in a very similar way to RGB values.
Hex values are most commonly used in websites, as this is how they are written in code and they are recognised across all browsers.
CMYK (also called four colour process) is the most common colour profile for print use, and stands for ‘Cyan, Magenta, Yellow, Key’. It is a method where tiny translucent dots of four ink colours (cyan, magenta, yellow and black) combine to create an image. Each ink colour is printed on a separate plate and built up in layers to create the final print. You may be wondering why black isn’t just called black and is instead referred to as ‘Key’. The Key plate, in traditional colour separations, is the plate that holds the detail in the image. In CMYK this is usually done with black ink, hence it is easiest to think of it as black.
CMYK colours are formed of three values – The first being the value for cyan, the second being the value for magenta, the third being the value for yellow, and the fourth being the value for black. Each value will range between 0 and 100 as they work as a percentage. For example, white would simply be represented by (0% 0% 0% 0%).
CMYK is known as a ‘subtractive’ colour profile because each ink removes a primary colour of light from any white light that hits it:
Cyan ink reflects Green and Blue light, but not Red
Magenta ink reflects Blue and Red light, but not Green
Yellow ink reflects Red and Green light, but not Blue
So if we think of this backwards, via subtraction, it explains how the print process works:
Cyan and Magenta ink combine to only reflect Blue light
Magenta and Yellow ink combine to only reflect Red light
Yellow and Cyan ink combine to only reflect Green light
The easiest way to tell if a print has been produced with CMYK inks is to look at it through a magnifying glass. If it’s a CMYK print you will be able to see all of the tiny individual dots making up the image.
PMS stands for Pantone® Matching System and these are often just referred to as Pantone® colours. They are solid colour inks made by the Pantone company. Pantone has been around for 60 years and introduced a standardised system of creating and matching colours in the graphic design and print world. Pantone® colours are sold to printers either premixed or as a formula for printers to mix on their premises.
Unlike CMYK prints, PMS prints result in a solid colour, so you wouldn’t be able to see all of the tiny dots if you looked through a magnifying glass. This is a very clean, exact way to print, but is therefore also more expensive. As all of the inks are pre-mixed, the more colours you introduce, the more expensive it gets. So this method of printing is most commonly used on prints with less variation in colour. For example, a business card print with a purple and turquoise logo and purple text, as this would only be a two colour job.
We hope this helps to explain the different colour profiles and how they all work. If you have a design job that you need help with (whether for print or digital!) get in touch at email@example.com.