Color To Black And White Live Stage Effect

The presenters and dancers in the background walk onto stage, the gal's dress is bright blue, the man's wearing a red rose, their skin is pink (if they're white) and the dancers and set props are very colorful.

Then they introduce the segment about classic movie history, the music swells and they say "Let's step back into a simpler time, where the good cowboys wore white hats, damsels were in distress and heros where fast on the draw..."

then BAM! everything on the stage turns to black and white, and they do their tribute to black and white movies, tv or whatever.

What you'd do is have everybody wearing black and white makeup with a semi transparent overcoating of colored fluorescent makeup. Their clothes would be black and white with a translucent covering of fluorescent colored cloth and the black and white stage props would all be similarly treated.

When they first walk out the white lights are augmented with bright ultraviolet lights causing the colors to fluoress and glow, but when the the uvs are turned off, the color turns off with them.

I think when mixed with the white lights the uv illuminated colors should look natural enough to make it a surprise when they turned off and everything goes black and white.