I know what you’re thinking (and not necessarily because I’m wearing a colored hat): this is about six things and not four. But wait, notice how the six thinking styles form three pairs of opposites:
Creative (Green) pairs with Process (Blue)
Positive (Yellow) pairs with Negative (Black)
Facts (White) pairs with Emotion (Read)
Then the three pairs of opposites can be arranged into a tetrahedron, where the opposite edges are the three pairs. A tetrahedron has four vertices and four faces, where each vertex is the opposite of its opposite face.
The vertices are Creative + Positive + Emotion, Creative + Negative + Facts, Process + Positive + Facts, and Process + Negative + Emotion. The faces are Creative + Positive + Facts, Creative + Negative + Emotion, Process + Positive + Emotion, and Process + Negative + Facts.
The first link below lists the same opposites for the Six Hats as I found. And there are also a huge number of links out there devoted to the Six Thinking Hats, so I can’t list or summarize them all, or even a small portion.
Edward de Bono / Six Thinking Hats
… and many more.