Really cool you chose to do an image processing demo with the "color grading" example. That is such a natural fit for visual programming. I could see Luna fitting into a video post-production or digital asset creation pipeline for games. The combination of a visual interface and functional logic could be used to create mind-blowing custom procedural solutions! Have you given any thought as to what media libraries you might use for the final stage rendering of audio, video, bitmaps, 3d scenes, etc. Because I think it's possible it may be entirely done in HTML5 / JS...
Keep up the good work!