A collection of guideline laws used to evoke emotion, set moods, and manage user attention with application of color
Colour theory is a collection of laws, guidelines and interpretations which guide the selection and use of colours. In user experience design, the meanings associated with certain colours and colour groups is particularly significant.
There are two broad colour groups: warm and cool. Warm colours (e.g. red, orange and yellow) convey happiness, enthusiasm and positivity. Cool colours (e.g. green, blue and purple) can be used to create calming and relaxing environments.
Individual colours also have their own meanings. Red can be used to convey importance or danger; error messages and delete buttons are commonly red to make the user aware of this. Green can be used to reassure the user; success messages and primary buttons make good use of this colour to tell the user that everything is fine or that they are safe to proceed.
Beyond concerns of clarity and visual appeal, designers can consider the perceived meaning of the colours they use to strengthen the messages they are trying to deliver.