Colour transformations as a post-process
I’ve added colour transformations to the Glow engine as a post-process.
Right now it supports contrast, brightness, black and white, and red, green and blue shifts. Saturation will come later. All the transformations run in one pass, so adding contrast on top of brightness, for example, doesn’t make it twice as slow.
The transformations are scene properties, so scripts can change them.
The original image:

Brightness adjusted:

Blue and green shifted for a Matrix look, with brightness adjusted:

Black and white:
