A re-creation of the physical two-strip technicolor process. State: beta.
twostrip offers a basic level of controls over how the input is treated and separated. There’s also an option to output the strip mattes instead of the final treated image, so you can use your own grain or go completely nuts with it.
You shot that Errol Flynn spoof in tights with lots of goofy sword fights? Here's the color treatment you want.
Photo from my holidays. Left side's the original colors, right side treated with twostrip (initial settings).