use pinstripe or model paint, same as for the color touches on emblems, no prep except good cleaning, expect to need redoing it over time, those look like the stamped stainless shell type
"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir "When we tug a single thing on an old truck, we find it falls off" ~ me Some TF series details & TF heater pics
