Sure does look like crap as you say.
But I will rescue you.
First remove the white crap as you call it.
If you are good with thinner base products it will be easy to remove.
Wipe with thinner base fast and swift motions to prevent meltage of the plastic.
'
Always have a wet rag to follow to break down the chemical reaction.
Ex chem guy.
Take a panel to an automotive paint store and they can easily and I mean easily match the color.
Or they might have the code available.
Clean the panel and provide light coats and I mean light coats to the panel.
Maybe 10 light coats each waiting for a hour to remove the flash and set the bond.
It will look perfect.
Bob's your uncle!