have you check the picture settings (colour etc)
then again it could be a loose scart connection at one end or the other if you getting a signal from outside sources
Could somebody have "fiddled" with the colour settings as a joke, or accidentally? Go into menu, settings, colour and try increasing it. Did it suddenly lose colour while being watched?
Thanks for your answers. It might be worth checking the picture settings, but there is no chance of anybody messing with the settings, as she lives on her own. Talking to her, I find she has only had it since March and she got it from Argos, so hopefully they will see to it for her, I am going to enquire tomorrow for her.
Now this is a mystery. Today the TV is working OK, full colour as normal. We had a power cut this morning, and when the power came back on everything was OK.