3. Perception: Colour and Sound

COLOUR

Over millions of years humans have evolved to associate colours with what is happening around them.

RED = Danger, stop what you are doing
GREEN = Everything is OK, keep going

So an interface that uses Red to indicate that they have done something correctly is confusing.

SOUND

The quality or nature of sound has a strong impact on what people think is happening

High pitch, melodious = A positive, affirmative action has been made.

Low pitch, staccato sound = A mistake or error has been made (For instance on television, giving the wrong answer in a quiz show often results in a harsh low sound 'Uh-Uuuh')

If you designed an interface that had to provide a sound alert when a problem occurs, then it is best to use low pitch rather than high pitch.

Do not make it loud or unexpected though, as that will only startle people. On the other hand, if you need to indicate that the action is correct, the use a high pitch, melodious sound.