Every palette that feels right in digital already exists somewhere in the physical world. Sunset at 6pm in October. Wet stone. Water at different depths.
Natural Gradients is a palette system built from observation. The software grid starts from theory. The physical world starts from experience. There's something in that gap I keep returning to.
You want completion to feel like rest: think about putting down a heavy bag, pushing a plate slightly away after a meal. The weight releases. Nothing immediately demands the next thing. Find those moments. They're your raw material.