The 6 thinking hats are a unique thinking tool for group and individual discussion.  This system, developed by De Bono, works on the principle of parallel thinking – allowing groups to think together more effectively, planning their thinking processes with more details. 
The human brain thinks in a number of distinct ways which can be identified.  This is a structured way for groups to develop strategies for thinking about particular issues.

Six distinct states in which the brain will identify and bring into conscious thought certain aspects of issues being considered, each states is being assigned with a different color.

  • Questions (White) – considering purely what information is available, what are the facts?
  • Emotions (Red) – instinctive gut reaction or statements of emotional feeling
  • Bad points judgment (Black) – logic applied to identifying flaws or barriers, seeking mismatch
  • Good points judgment (Yellow) – logic applied to identifying benefits, seeking harmony
  • Creativity (Green) – statements of provocation and investigation, seeing where a thought goes
  • Thinking (Blue) – thinking about thinking

Colored hats are used as metaphors for each state, helping people to think deeper for a better learning.

White hat (Facts & Information)
Participants make statements of fact such as identifying information that is absent and presenting the views of people who are not present in a factual manner. Key absences of information can also be identified at this point.

Red Hat (Feelings & Emotions)
The red hat is used to review personal progress or deal with issues where there is high emotional content that is relevant to discussion.- Request an aesthetic response to a particular design or object

Black Hat (Critical Judgement)
Participants identify barriers, hazards, risks and other negative connotations.- Critical thinking to look out for problems and mismatches.

Yellow Hat (Positive)
Participants identify benefits associated with an idea or issue. Opposite from black hat thinking, the yellow hat looks for reasons in favor of something. The outputs may be statements of the benefits that could be created with a given idea, or positive statements about the likelihood of achieving it, or identifying the key supports available that will benefit this course of action

Green Hat (New Ideas)
This is the hat of thinking new thoughts. Based around the idea of provocation and thinking for the sake of identifying new possibilities. It is often carried out on black hat statements in order to identify how to get past the barriers or failings identified there.

Blue Hat (The big picture)
This is the hat which all participants discuss the thinking process. Having a facilitator maintain this role throughout ensures that the group remains focused on task and improves their chances of achieving their objectives. The blue hat is also an organisation of thinking.- What have we done so far? What can we do next?

With a good mediator, deciding on which hats the group wears, this is a great way to develop new ideas.  Can use this in conjunction with other brainstorming tools.