The Yellow Hat
A situation or solution is examined in terms of its "positive scenario". The advantages, the assets, the strengths. It is also a rational hat: you have to argue your points of view. If it can work, it is because there are arguments that allow this optimism. Questions to ask yourself could be:
How is the current situation good? What are the reasons why this solution would work? What are the strengths of the project that has been carried out? What gives the project a chance of success?