70's Zenith

I have a similar chromacolor II but probably just a a year or two older. Same white pedestal base etc. The picture and sound are great but the color is all messed up. I am new at this so please be understanding.

What can I do to fix up the color?

1. Most of the time it is greenish.

2. Sometimes some of the colors come in

3. None of the picture or color adjustments on the front or back of the television do anything.

4. I love the television and would like to keep using it.

Thanks