Philips 109P4 Trinitron CRT

It doesn't sound like you've got any experience troubleshooting electronic circuits. Do you know anyone around you who does?
I can't see your problem, but this is basically what would need to be done:
1) Only somebody familiar with CRT's should mess with them, because there's high voltage on the tube anode
even when the power is off. It's stored like in a capacitor.
2) In the old days a lot of repair shops had 'picture tube rejuvenators', to try to solve your weak green gun.
3) It may be in the neck of the tube, but you probably have damage on the color/convergence board itself that is
causing your excessive red.

Somebody familiar with old CRT displays would know what to look for. Nobody here will recommend that you
try to fix this by yourself with little to no experience, because of the dangerous high voltage involved.
If you don't know anyone around you who has experience with this type of display, you really should just
trash it. And if the CRT tube itself did go bad, NOBODY can fix it anyway.

 

You need somebody old enough to have worked on CRT displays. New techs don't know anything about them.
If you're going to trash it, believing it unsalvageable and not worried about damage you might cause, I'd open it up and take a look inside the housing before throwing it away.
If I remember right, the Trinitrons are front-heavy. All the weight is in the front of the CRT, and the back cover is
very light by itself. If you take the back housing off the display, lay the set face-down, on the front of the CRT, and
remove the housing screws so you can take the back cover off. If you try this with the set standing up normally, when you remove the last screw from the back of the housing, the CRT heavy assembly will fall forward, and maybe
off of whatever work-surface you're using.
If you take the back cover off, just look inside for excessive heat damage to components. I'd be paying particular attention to the color circuit. Sometimes a small board attached to the yoke around the neck of the CRT tube.
sometimes on the board the yoke wires are attacked to elsewhere. I believe you'll find a component burned-up on
that circuit that resulted in your excessive red on the screen.
I'm just suggesting this as a last-ditch effort to save the display. Not knowing much about troubleshooting and repair,
you might further damage something in this process, and I disclaim any responsibility for that.
If you find burned components, maybe then 'the maintenance guys' there, can identify the problem for you and help identify the bad component(s).
You probably can't tell for certain if your green is weak because it's being washed-out by the excessive red. But even
if you get the red circuit fixed, you may still have weak green.
Trinitrons are nice displays, but they were always expensive to fix. My suggestion here is, like I said, just a last-ditch
check to see if your problem is a simple one or not, before trashing the display.
The high voltage on the CRT is at the larger diameter wire/plug that is attached directly to the back of the large CRT tube. Stay away from that.
I hope it's needless to say that the power cord needs to be unplugged, before you attempt any of this.
Just a thought, in case you want to look at what you have before throwing the Trinitron away, and I wouldn't blame you
if you just disregard what I said here, and trashed it without trying to disassemble it.
Stay safe and good luck.