if you are talking the silver behind the lense on the housing itself...thats a chrome like plating. i d use some rattle can chrome paint. as long as you seal it good...you won t have to worry about it discoloring. tip...if you wanna make that pot metal housing look like new...dunk it in a bucket of miratic acid for about ten seconds. it will turn dark grey and kinda slimy. scrub it right away with fine steel wool and dish soap. makes that pot metal look brand new. easy to do. afterwords you can wipe the housing with w-d40 and it ll look new.
