Although many visualisation techniques employ graphical devices for the display of information, visualisation may also be used to invoke 'visual metaphors' that can help invoke particular ways of thinking; sometimes, these metaphors may have little or no literal connection at all to the invoked image, or they may have an entirely arbitrary connection. It does help if they are memorable, though!
Take for example de Bono's "Six Thinking Hats®" method for invoking parallel thinking about a topic or decision, as described in the video below:
What are the colours of the Six Thinking Hats®, and to what sorts of thinking does each relate? To what extent do the colours invoke the corresponding style of thinking in a natural, 'visually evocative' way?
Would the style of thinking for each hat be as effective if the colours were matched to thinking styles in a different way?