
Why does the same colour look different in different places? - The simplest way we find to explain the differences in colour is to go down to your local PC World or Curry’s and look at the wall of TVs. They are all usually showing the same program or image, yet the variation in the colour between each screen is easy to see, isn’t it? This is down the independent colour space of each TV, so don’t trust the colour you are seeing on your screen to be exact, and certainly don’t trust that you’ll be able to emulate its appearance when you print it.
There is even more difference between a colour you see on a screen and the same seen on paper (or on textiles, or on a sign). But before you lose all hope and simply do everything in black and white, take heart that we have all the measures in place to get your colour reproduced as accurately as possible.
What is colour? - Simply put, colour is formed by light reflecting off a surface and hitting our eyes. White light contains the full spectrum of visible colours. Each colour has its own wavelength. We see the spectrum in a rainbow or on the cover of Dark Side of the Moon. Different objects reflect different wavelengths of light and so appear as different colours. For instance, grass looks green because it reflects green light while absorbing all other colours.
What is the RGB Colour Space? - RGB stands for the three primary colours of light: Red, Green and Blue. Colours in this space are created by mixing varying amounts of these three lights. TVs, monitors and digital cameras use RGB to simulate colours.
What is the CMYK Colour Space? - Cyan, Magenta and Yellow, together with Black, are the primary colours of pigments like inks and dyes. You will remember from primary school that mixing cyan (a blue) paint with yellow gives you green paint. Likewise blending cyan with magenta (a red/pink) results in purple.
The initials of Cyan, Magenta, Yellow and Key name the colour space. The key colour was traditionally added last to a printed picture to highlight fine details and border it with a keyline. Black was most commonly used and so found itself as the fourth process colour.
‘Process colours’ and the ‘four colour process’ are synonyms to describe printing using the four CMYK colours.
What is the difference between RGB and CMYK? - Both colour spaces exist to define recipes to reproduce colours. They take very different routes to get there though.
RGB is an additive system. Adding more and more colours as light leads you to a bright, white result. Switching off light/colour gives you darkness or black.
CMY(K) is by contrast subtractive. All the pigments on top of each other on a page would be black. Subtracting them would lead you back to blank, white paper.
To show a red on your laptop the red diodes in the screen are switched on and the blues and greens are switched off. A printed red however needs a mix of magenta and yellow on the page.
You have probably already spotted the problem here: one colour, red, with two recipes to create it. Those recipes also use completely different ingredients.
To make life harder, RGB is device independent, meaning there is no guarantee that the red on one screen looks the same as the red on another. Even though they are both using the same recipe, the final output will be different.
To make life even harder, the range (or gamut) of colours you can make from CMY(K) is narrower than with RGB. The RGB gamut reaches more colours which also tend to be more vibrant.
What is the solution? - How do you maintain consistent colours between screen and print?
What about between screens? And how about between leaflets and signs?
There are some simple things you can do to help eliminate the possibilities of a colour not reproducing as expected:
Calibrate your monitor. Give yourself confidence that what you’re seeing on your screen is a true representation. Monitors sharing the same calibration set-up should display colours in a similar way.
View your work on screen in good lighting, preferably against a neutral grey surrounding and background. Every bit of colour in your range of vision will interfere with your eyes’ interpretation of a colour.
Try to make sure the software you are using is configured to match the settings used by your printer. Adobe software is shipped Worldwide and by default is configured to US standards. In Europe we print to a different baseline. Japan is different again.
Perhaps the biggest thing you can do is make sure you’re designing your artwork in the CMYK colour space and not in RGB. If you use software like Microsoft Word and PowerPoint, you should be willing to accept that the printed colour will likely be nowhere near to how it displays on the screen. Those brightly coloured rainbow effects are going to reproduce quite flat and dull in relation to how you are seeing them on the screen.
No, forget our last comment. The biggest thing you can do is manage your expectations, accept that the colour may reproduce differently to what you might think, embrace it and love the result we’re able to provide you with.
Is RGB or CMYK best for print? - RGB works on screens and so is the best model for designing websites, apps etc. CMYK is designed to economically reproduce as many colours as possible on a surface. CMYK is best for print.