Colour distortion at the sides of the picture

Question

I have a Sony Wega KV-24LS35U and quite suddenly, with no warning and whilst watching the televsion, I noticed that the colour at the sides of the picture (about a 3-4 inch strip) is distorted and seems to be complementary colour to the correct one - For example green becomes pink. Is this something that can be rectified or is it a terminal problem with the CRT. I have tried simply turning the television off and on again and this makes no difference.