it actually is no different, except i make the brush more translucent and apply it many more times. its still just oldcolour*(1.0f-opacity)+brushcolour*opacity. just opacity is much smaller and done many times.
it has a bitcrushing effect on the colours, its really nice. Ill have a decent picture to show tomorrow, hopefully - at the moment the pictures here are pretty crap, ill use it decently tomorrow.
note you can get the same effect in say gimp, (just put opacity to 0.5%, thats how i first worked this out!) it just takes ages to get anywhere, this program helps speed up the process and importantly lets you work backwards and forwards with the effect.
you used to be able to fit a game on a disk, then you used to be able to fit a game on a cd, then you used to be able to fit a game on a dvd, now you can barely fit one on your harddrive.