I stumbled on this almost accidentally, but really like the visual effect.

I'm using circular modules. I set the light modules to just barely off white — [244, 244, 244]. Against a white background it makes the QR almost... shimmer. If I hide the light modules it looks nice, but if I show the light modules against a white backdrop it sort of dances to the eye. It's really subtle — I would have a hard time recognizing exactly what it was if I hadn't done it myself.