Here’s a recap on the technicalities of Additive and subtractive colour reproduction…
or RGB and CMYK as you’ll probably know it.
RGB stands for Red, Green and Blue. It’s the colours which lie roughly at either extreme and the middle of the spectrum of light after it passes through a prism. It’s sometimes called ‘additive’ colour, because the three added together actually form pure white light – imagine them passing back through the prism in reverse.
The important thing to realise is that RGB is how your monitor (or your TV or mobile phone) displays colour, though activation of red, green or blue pixels. If the monitor is to display white, it will activate all three colours at that point.
Obviously one cannot print in RGB. Inks added together or printed over each other, as every schoolchild knows, doesn’t result in white, so the whole concept of the display and the print would be incompatible.
That’s where Cyan, Magenta, Yellow and Key (black) come in. Sometimes called ‘subtractive’ colour, cyan, magenta and yellow have been found to allow the closest approximation to RGB in print. Supposedly, these colours added together should produce black, but it usually comes out as a muddy grey; a black is therefore added, called Key (to distinguish it from blue).
As printers use subtractive colours, your photos and graphics will Read more