Coloured hat
In Tibetan Buddhist cultures, coloured hats are sometimes used to symbolise attitudes towards various different abstract concepts. Several sects are distinguished by the colour of their hats:
In computing slang, hackers and crackers are identified according to their intentions.
Also in computing is a business company called Red Hat.
In the educational theories of Edward de Bono, six coloured hats represent six thinking states.
In Chinese culture, a green hat symbolises a cuckold. This issue is addressed in the movie Green Hat.
