deSpill gizmo that allows to replace spill with color or image,

Homework

I tried different ways of keying, first I used IBKColour and IBKGizmo for the green screen removal, but I was not satisfied with the results at the hair, the edges of the hair nuances were very untidy and the lines were obvious, so I switched to other methods.

With SpillReplace, to do the colour replacement, I first used the keylight node to remove the green background, I used Erode and Edgeblur to soften the edges of the characters, used different merge nodes which are divide, multiply and above, added the Premult node which multiplies the input rgb channel by its alpha to merge the UN pre-multiplied images and colour-corrected pre-multiplied images.
I added Grade and ColorCorrect to the background to adjust the colour, based on the warm yellowish tones in the foreground, I needed to warm up the cooler tones in the background. This makes the two blend more realistically