Any better now?
I was thinking maybe putting some white epoxy over each of them and then when it's set, rubbing it back with some very fine grit wet/dry paper.
We have just had an extension built with white aluminium bifold doors out on to the patio/garden. I have been a complete muppet and upon getting home and seeing them for the first time I have opened them up without removing the keys, causing the below damage when the doors have concertina'd...