What is the difference between RGB CMYK and Pantone? The tricky thing is, that there is a lot more to colour management than you might think. While a colour you see on screen might be the perfect sky blue you are searching for, it is almost guaranteed that when printed it will look nothing like the colour you approved on screen. In the colour world, there are three main colour systems – RGB, CMYK & PMS. It is very possible that you have heard these terms before. It is even more possible that you have no idea what each of these acronyms stand for and which is the most suitable for each format in the design industry.