Simply 'paint' directly on the preview image, and Photon translates your strokes into a live 3D virtualization of the color model you are building. But you don't have to be a 3D artist to become a really good colorist. Instead, you directly shape a 3D color model. Grading in Photon works without layers or nodes. It can work as a plugin for DaVinci Resolve or as a stand-alone editor for still images. But a new application for Mac and Windows has a rather revolutionary interface that helps you visualize what your image values are and lets you modify them to your heart's content.
I understand what color grading and LUTs (Color Lookup Tables) are and how they can improve a photo or video.