.
A pic of 'Uncle Robin's ceramic coated tips for reference:
These are factory coated as supplied by Milltek. I'm not sure if they are an offered option.
Ceramic coatings are very easy to clean with a non-abrasive cream (I use Megs NXT) and also the tips are cold to the touch even after a long spirited drive of several hundred miles.
I don't know about how successfully a ceramic paint can be applied - In ignorance I would imagine the ceramic coated to be done under heat.