On the subject of the blue and magenta ball- I’ve seen materials that look like that in the real world, it was a specially coated mirror, I can’t remember what we used it for, but we were doing laser based imaging of live cells. If you held the mirror at the right angle you could see that the light transmitted was one color and the light reflected was another color.<p>Update: it’s called a dichroic mirror: <a href="https://en.m.wikipedia.org/wiki/Dichroic_filter" rel="nofollow">https://en.m.wikipedia.org/wiki/Dichroic_filter</a>