How to remove *all* green and blue light: xcalib and redshift seem not to?

I'd like to have a redshift-style effect on my laptop screen but where I truly remove *all* green and blue light, leaving only red. I've experimented with redshift, which doesn't seem to take it all the way, only redder, but neither it seems does xcalib... I had thought I could get this by running this: xcalib -blue 1 0 1 -a xcalib -green 1 0 1 -a But that seems to turn the screen orange rather than red -- perhaps it reduces the contrast in both directions (so makes the bottom end brighter too?). I'm confident that I'm right, and that that isn't a trick of the light, because if i run instead xcalib -red 1 99 1 -a ...then my black terminal turns definitely the sort of red that I wanted. Is there any way that I can achieve what I want -- effectively, cut out *all* blue and green light?