Try swapping red and blue drive lines. Isolates to the final or earlier
stages
Well, I'd start with centering the blue control, maybe the red and
green
too, then readjust the high voltage "screen" or "G2". You need a
grey-bars
test signal to readjust the color (first diddle the RGB offsets, to
get
the darkest bar neutral gray, then change the RGB gains to make
the lightest bar neutral).
Some monitors do a lot of this through software, but removing the case
back and poking in with small adjustment screwdrivers is the usual
procedure. Beware the high voltage (anode) wire; your adjustments
have to be made with power ON.