New here and to Vintage TV.

[DaveWM]

also since you are getting a B&W pic then all the guns are working. No color, I would start with the obvious, clean the color control, clean all the tube pins and sockets with your fav contract cleaner. Wiggle the chroma tube (burst amp, osc,demodulator tubes). if still nothing you can use a scope and check for waveforms with a sams, or just get some new tubes (I would suspect the 3.58mhz osc 1st). replace the color killer tube. Some times the color crystal will be bad, you may seen barber pole colors, sometime just a purple overall color, depends on just how far out of whack the osc is running. again a scope is best also voltage checks and tube replacement of the chroma tubes.