I never done it but I suggest you use a enamel that can withstand scratches and fingerprints.

I have painted other remotes with sprays (Glow in the dark). But when you put them down on a table after a year it can get worn through.

I never tried a spray enamel but that would be my choice. A brush would give it a thicker coat.

You could try cleaning the remote with a solvent to remove the rubber coating or sand it.

I have tried a spray Plastic Dip coating on something similar but it wore off. It peels off to easy.

Good luck.