Edward de Bono also known as the father of lateral thinking and creativity came up with the six thinking hats system so that organisations can be more productive, focused, and mindfully involved.
The six hats were coloured: * White * Yellow * Black * Red * Green * Blue

White
Facts (also known as white paper) - The people under the white hat are required to retrieve all of the facts that may be needed this includes all the data and information. They are also required to identify information that may be needed.
Yellow
Positive (also known as sun shine) - The people under the yellow hat are required to have a positive view of things and to look for benefits in the given decision or situation they will also encourage a positive view on the rest of the team.
Black
Negative (also known as a stern judge) - The people under the black hat will always be cautious of every decision or situation
Red
Feelings (also known as fire and warmth) - The people under the red hat will say what they feel without being judged.
Green
Creativity (also known as vegetation and rich growth) - the people under the green hat are required to be creative and to come up with new ideas.
Blue
Control (also known as the sky and overview) - the people working under the blue hat are in control of the process, they ask for summaries, conclusions and decisions .
Why Six Thinking Hats
Here are a couple of reasons for using Six Thinking Hats: 1. More complete thinking. Six Thinking Hats helps you leverage more complete thinking. In the Six Thinking Hats, each hat represents a different perspective (facts, emotions, critic … etc.) If you think of the problem as a pie, then each hat or perspective is a slice of the pie. If you only have the Devil’s advocate, then you’re missing several other perspectives. By cycling through the hats, you get a more complete view.

2. More collaborative meetings. By using the Six Thinking Hats, you can get everybody thinking about the problem in a collaborative way. Everybody can put on the same hat at the same time. The real key here is that rather than circular or deadlock debates, you focus the group on a particular viewpoint at a time. This is a similar to writing, then editing vs. editing while your write, or brainstorming, then critiquing vs. critiquing while you brainstorm. The big difference is that rather than just brainstorming and critiquing, you’re looking at the issue from multiple, specific angles. On the people side of this technique, you’re letting people wear a different "hat", in a safe, constructive way.

When to use it
Use it in teams where you want to use different types of thinking.
Use it where individuals would feel inhibited by taking these roles without prior legitimisation.
Use it to encourage further use of a range of thinking processes.
You can use it to explore ideas when selecting which to take forward.
You can use it to explore how other people will react when you try to implement your idea.

Why I chose the yellow hat
The reason I have decided that I am under the yellow hat is because I believe that I am someone who thinks positively and and always looks for the benefits of an idea and I am able am able to support why I think it is good I also I can provide reason to why it is valuable for example “if we start advertising then the business will attract more people and make higher profit”.
I can also answer question like can this solution be made to work, will this idea work in practice and can we estimate feasibility given the existing system.

References: http://sourcesofinsight.com/how-to-use-the-six-thinking-hats/ (2009, JD)
http://creatingminds.org/tools/six_hats.htm