Dampen a cotton cloth with a small amount of naphtha and wipe all of the rocker switches clean of oil, grease and dirt. This will promote adhesion of the paint. Naphtha can be replaced with electronic contact cleaner, but both chemicals are component safe as long at all electronic equipment is unplugged.
Paint each rocker switch with enamel model hobby paint with a fine tipped paint brush. Use as many colors as needed for your application. Enamel paint will prevent the need for using a hard top coat to cover the paint. Enamel paint will last for a long time.
Accelerate the drying process by blow drying the the rocker switches with a blow dryer set to low heat. Hobby paint will normally dry within 24 hours, but in the event you need to use the equipment it can be accelerated with a blow dryer.