There is much to colour theories in design. There is the colour wheel, the components of a colour, psychological properties of colours and much more. Knowing and understanding the colour modes will make a good start. As designers, we encounter two primary colour modes – RGB and CMYK mode. While we may be capable of choosing the correct mode for our design projects, do we really know the differences between them?
The RGB Colour Mode
RGB is the acronym for the primary colours Red, Green and Blue used in the RGB colour mode. Red, green and blue are the basis for all the colours you use on screen.
The RGB colour mode uses an additive colour system which works on light emission or radiation. We use the RGB mode for designs that are to be displayed on screen or through a projector. Good examples of design projects that are displayed on screen would include website design, marketing graphics used on social media platforms, eNewsletter and eCard.
In the RGB colour mode, white is the combination of colours and black is the absence of colours. This is the very reason why an unpowered screen is black in colour!
On online mediums, the hexadecimal colour mode is used as widely as the RGB colour mode. HSB and Lab colours are less commonly used.
The CMYK Colour Mode
CMY is the acronym for the primary colours Cyan, Magenta and Yellow used in the CMYK colour mode. Wait a minute… What about ‘K?’ ‘K’ represents ‘Key’ in the acronym CMYK and it is simply the colour black. Why do we need this additional colour? CMY is an imperfect colour system. The closest to black we are able to achieve in print would be an unsatisfactory dark brown. Without the colour pigment black, we can never reproduce black in our printed collaterals.
The CMYK colour mode uses a subtractive colour system which works on the principles of reflected light. As graphic designers, we use the CMYK mode when we create designs that are eventually going to be printed. Print designs can include anything from a business card, poster, brochure and annual report.
In the CMYK colour mode, black is the combination of colours and white is the absence of colours. In printed medium, the colour white is not printed (unless the project specifically calls for white ink to be printed). White, or rather, the absence of colour is taken up by the actual paper colour which the design is printed on.