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When using colour as a coding mechanism, the number of colours used should be:

a. 7 or fewer b. 9 or fewer c. 6 or fewer d. 8 or fewer

Potentially a question for cognisc Stack Exchange but this question relates to the amount of colours a user can perceive at a given moment and in terms of UX, I guess, assigning colours to categorise elements.

For example, how many colours can the human brain take in at a given moment of time without over-complicating a design. For example, according to Dr Halberda (2006) colour plays a major role in catching the attention of people. One can select and attend up to 70 items at once if they are of the same colour. Colour-coding helps to keep things organised and simple. But what Halberda failed to account for is how many colours can be categorised at a given moment in time.

These are the only answers providing by the organisation body so unable to give a min or max answer. The meaning of fewer is less

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marked as duplicate by Ben Brocka Jun 11 '13 at 17:57

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

Needs much more context. What is the max number, what is the min number? What is the meaning of ewer? – rk. Jun 11 '13 at 15:21
You mean like the colour coding in the new Gmail app? – AndroidHustle Jun 11 '13 at 15:48
Edited comment to account for context.@AndriodHustle - similar yes, so how many can we interpret at a given moment without forgetting what each colour is intended to represent? – UserConversion Jun 11 '13 at 16:20
Can we remove the multiple choice options from the question? It sounds like you want us to answer an exam question for you. – Matt Obee Jun 11 '13 at 16:27
You might be interested in Trello's treatment of the subject, regarding its use of colored labels as well as being able to switch to patterns instead of colors for color-blindness:… – jzx Jun 11 '13 at 17:34

We don't know what precisely you want to do with colours. But don't rely on colour alone to convey information. Otherwise your work would not be accessible. There are colour-blind people. And, if you do use colours, choose colours not close to each other.

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