Colourful designs

Colour can be a bit of a minefield in design. I once asked for a colour reference and I was sent a Dulux colour chart!

First things first, no matter how expensive your kit is, what you see on screen will not be what you see on the printed sheet. It is also unlikely that it will look the same on other peoples' monitors either. Macintosh and PC monitors vary hugely, then there is the lighting conditions, the monitor settings and whether the user is wearing rose tinted glasses or not. You should never be in a situation when your printed job has been delivered and the words “it doesn’t look like that on screen” come out of your mouth.

Here’s the science bit; things look different on screen to the way they look on printed paper because there are different types of light involved. One is projected light, the other is reflected light. There is also a thing called gamut.

Gamut is the scope of something, in terms of colour it is the range of colours that a certain technology or process can display. Back to that in a minute.

Reflected light is what you see most of the time, reflected off paper, off flowers, reflected off someones face. Your eye can only see a certain spectrum of colours, it has a limited gamut, colours like infrared and ultra violet, humans can’t see, they are out of our gamut.

Projected light is usually fired out of ‘guns’ inside a monitor, it uses a mixture of three colours, to create colours. These are Red, Green and Blue (RGB). Assuming the range your monitor is set to millions of colours, there is a wide range of colours that can be shown, all within the human gamut (otherwise you wouldn’t be able to see them).

‘Traditional’ litho printing does not have a gamut as big as the human gamut. The technology isn’t there to show all the colours our eyes can see. Monitors, however can show a wider range of colours and they can appear brighter.

Colours used in litho print (and almost all digital print) are made from inks. In the case of full colour (or four colour) printing, these are cyan, magenta, yellow and black – CMYK, the 'K' stands for Key Colour.

Colour modes and colour pickers
It is always best to select the colours using the correct colour picker (or palette) and that fit in the right gamut for the output. So, if you are doing a full colour job, use the full colour picker and sliders. If you are doing a CD-ROM, use RGB and if you are designing a website that needs to accommodate the lowest common denominator in terms of a screen technology (excluding mono) use Websafe colours.

Rule of thumb for colours:
Use CMYK for full colour printing
RGB for screen outputs
Pantone or similar for ‘spot colour’ printing
Websafe (or 16x16) for low-end websites where the lowest common denominator in terms of technology needs to be accommodated.