this is great! I did find parts of the UI a little confusing though... Should the input colour update when I change source? And after saving a project, I am not sure how I can re-open it. Maybe it's just me but I didn't immediately realise that the nodes on the left were draggable (i see now that it is mentioned lower down). Maybe add "drag dots" to those? Really nice tool though!

Looks cool! I can't get new Color Relationship nodes to work, though. The initial one works, but any new ones that I add don't use their input