Zenith Chromacolor troubles

[Doug]

I would try turning the color off. If its still there then look in the video area , and of coarse if it goes away look at the color circuit tubes.
Maybe when rechecking the tubes ckeck for filment to cathode shorts. May want to tap on the tubes with a fiberglass insulated rod to see if any change.
Also maybe its the way the wiring is placed such as yoke wire to close to the video section.
Does it do it off channel or with the tuner unplugged? Maybe some kind of oscillation.
Hey I can be off on these statements its been a long while since I worked on tube types.