1. Colour scheme
A secondary colour is simply a colour made by two mixing colours in a given colour space.

2. What it is?
A colour scheme is basically the choice of colours used in design for a range of media. For example the ‘’Achromatic’’ use of a white background with black text is an example of a basic and commonly default colour scheme in web design.

3. Primary colour
A set of primary colours, is most tangibly, a set of real colorants or coloured lights that can actually be combined in varying amounts to produce a gamut of colours.

4. Secondary colour
A secondary colour is simply a colour made by the mixing of two primary colours in a given colour space.