Paint for plastic bumpers

I wanted to get the grey colour back on my bumpers.  They have been touched up in satin black spray paint up to now.  Anyone recommend a colour or how/what to put on….get a tin from halfords or a specialist paint??

If they have been painted you can just key them up and repaint with normal paint. If not you ideally need to use a plastic primer type paint, works on the same principle as acid etch on metal.

Funny isn't it, you like your grey bumpers but I didn't and chucked them away!!!!

Still prefer black ones!