The trick to washing out color is . . . . . . so that only that color reflects . . . . . .
Some what the opposite, so the color is not reflected. Since light/color is a reflected value , if I want the person on
stage who is wearing a red costume to appear black, I would shine a green light on them. Since the red will absorb every color but red, it will turn (relatively) black because there is
no color to reflect back to our eyes. However if there are any green or white costumes then they will light up. So, this may take some intricate planing with the director/costumer as to
stage areas to group colors. (In the same way you can take a secondary color and make it flip to one of the primary's in it.)
So the debate rages on..... can you project black? Since grey is a mix of black and white. I hold to the view that you cannot project black. Therefore using r98 to cut light will not really do that because it is just cutting the light output. I does prevent the light from shifting to amber/red like it would if you just dimmed it. Perhaps getting to a sepia look may be possible if the director will go for it.
So to create a black and white look you will need isolated areas in white, like a
cyc or building with white light. Then only light the areas with color with a
gel that is not part of that color. as stated earlier it is not
practical on a general
stage because any
spill of the color onto the white will cause it to not be white.
Now think outside the box. . . . . dropping a black
scrim, or back light with blinders, or . . . .