Many moons ago I did Edward de Bono's Six Thinking Hats Short Course at the Melbourne de Bono institute. We also covered some of the material in the Lateral Thinking module of the Course in Creativity
This is halfway through an earth, water, air, fire set. Earth - is represented by brown spirals - semi-inpsired by the triple spiral at New Grange in Ireland. Water - represented by blue bubbles. Seemed the natural thing to do with Spheres, clones and gradients.