Colour Gamuts
This image shows the different colour spaces on offer. If you were to use your info window within Photoshop on images with colour space that are set in RGB you may find it would display an "!". This shows you that the colour picked is not within CMYK, in other words the colour is out of gamut. To understand the reason for this please look again at the image above. CMYK colour space is smaller in area than LAB or RGB.The white space around the CMYK image illustrates the area that cannot be reproduced in CMYK but does exist in LAB. It is always important to consider the colours you use as to whether or not they can be reproduced within CMYK. Far right of the image is an example of how the computer converts colour into CMYK to give you some idea of how important it is to consider the colour you use.
A further overview, which can be viewed in Shockwave, is available by clicking here
*CMYK
is short for Cyan, Magenta, Yellow and Black. These are the four colours which
are used within 4-colour process and create the majority of magazines and
books produced in the commercial world of print today.
**RGB is short for the primary colours Red, Green and Blue. This basically
is the colour space which the screens use to display colour.
***LAB creates consistent colour space. Originally created as an international standard in 1931 for colour measurement