A hilariously cheap gimmick.
What I'd be interested in, is to see is how this performed.
http://earlytelevision.org/pdf/pop_elect_10-68.pdf
http://earlytelevision.org/butterfield.html
If the effect is real, with today's cheap electronics it probably would not be hard to demodulate a color signal to RGB, re-matrix to YMC gate which one is shown each frame and re-modulate it as perceptual color 'monochrome' video. If I manage to un-bury myself in repairs, that project is high up on my "I want to build this" list......If it does work and I can build the circuit I'm thinking of, I know which set to test it on...One night about 6 years ago I dreamed my 19" monochrome Zenith Space Command was producing a color picture, unmodified (it'd be neat to see that).