Yes, that's nice but I already knew about it :)
My point is that I can edit my main set of pictures by replacing a color and then creating a new set with that color.
Or I could upload a single set to the viewer with special areas selected for the viewer to process (let's call it green screen)...
I will use webrotate on my rubber stamp selling website. Each stamp can have 6 outer colors and I need to be able to switch between them.
I could create a set of 6 x 36 images, each with a different mask applied that would change the color. But that would mean the customer would have to wait...