Sony KV-M2511U

FAULT
After switching on, the picture has a green hue. This disappears after a
few minutes. Often, the picture is normal after switching on.

COMMENTS
The TV is probably 12 to 14 years old, so we've had good use from it, but
I was wondering whether this fault might lead to a complete failure in the
future or further steady deterioration.

Also, does anyone (a TV engineer maybe) have a diagnosis for the fault
described and know whether it would be worth repairing.

Thanks in appreciation of your replies.
Paul