I came across this Isolite project on kickstarter. At first I thought it was complete BS, but basically it proposes exposing an image using two colours of light (maybe more?). The different lights can then be mixed down to create a monochrome image with a variable light pattern. I'm really not interested in the over-hyped kickstarter project, but it's an interesting idea. As far as I can see it only needs a couple of theatre gels and a decent image editor to make it work.