Here's a video of my problems, a good working WG6100 vs. another one that was just re-capped... Check out the problem, it's better than trying to explain, but some colors (like the green landscaping) don't show up on some screens..
What happens when you turn the brightness up? Adjust the color pots? The color pots on a 6100 are kind of weird, in that you turn them in opposite directions to get the color to optimum levels.
As for green, check Q501 on the neckboard.
And it might need a rejuv, as previously stated. Swap all the boards over to the other tube and see. Start with just the neckboard and see if the problem moves...