My Mum wants to paint some shutters, I said she shouldn't but she says that you can paint upvc.
Isn't the whole point of it to save on labour?

I wouldn't, you need special paint. We do it at work (I work for a major conservatory company) using special paints that bond into the PVC (process is called colour bonding). If you use normal paints from B & Q it won't adhere properly and is going to look a right mess.

If you can remove them you might be able to get them properly colour bonded, we use a company in Rochdale called Colour Code. Not sure if it would work with weathered upvc though.

Try upvc cream cleaner first. Works a treat, screwfix sell it, probably get it in b&q too. I normally use the wurth stuff, followed by solvent cleaner if really bad. Both applied with a microfibre cloth and lots of elbow grease

Try upvc cream cleaner first. Works a treat, screwfix sell it, probably get it in b&q too. I normally use the wurth stuff, followed by solvent cleaner if really bad. Both applied with a microfibre cloth and lots of elbow grease