How do I fix my colour on my TV?

My colour tv at first lost the colour and would go black and white when I played a dvd player on it. I first noticed it go black and white before i plugged the dvd player in on my digital vcr. It went black and white at times. Eventually the cable colour went. I could watch tv for a while before it goes black and white. But now it goes in seconds. I was told it could be the digital processor. I have a mitsubishi tv. It is about 10 years old floor model excellent stereo sound. model no.
ck-2698c. Can anybody help me out on this? I know how to solder but not sure what i am looking for.