Color is gone in a sony kv-c2963e tri...

as you say that color came back for 15 minutes then went off.
this is a clear indication that there is a loose contact or pcb crack somewhere in color section only.
if that happens to be ok then check
1 antena or cable socket loose
2 loose connector in color section
3 print open or crack near chroma signal processor.
4 loose near color control.
5 chroma ic night be defective.
if you are not tech person take the help of tech.person.