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.