Colour Modes: RGB or CMYK?

Have you always wondered about the difference between the RGB and CMYK colour modes and how it will affect your final production?

It is important to understand their differences so that you can plan your workflow and optimise each stage of your design process because this will have an impact on your production.
When designing with the intention for web display or digital screen, there isn't a need to worry about colour modes as colours look similar on most computer monitors (they're all capable of displaying a range of colours in the RGB colour mode).
Colours displayed on computer monitors, scanners and digital cameras utilise the red, green and blue (RGB) light.  RGB is the standard colour mode throughout most applications because it offers the widest selection of colours. By combining the primary colours (red, green and blue) in varying amounts, you can achieve any colour you like with great accuracy. Almost all photo-editing programs use the RGB colour mode as standard which is why you need to be extra careful when designing for print.
When designing for print, it's wrong to assume that the colours you see on screen when creating your design will remain true-to-life when printed.