Generally turn the color off, some units require unsoldering
the color crystal, but not this unit. If the G2 & other pots like
ABL, weren't fooled with, turn the red, green, & blue to minimum,
then try about 25% red, then mix in green to look orangy/yellow,
then mix in blue to get "true B & W". It's easier to do, than say.
You just do it by eye. If you fool it up, & say it looks too green,
just reduce, & mix green, & blue as needed. Sounds like mixing
paint for a car. Sky