And I'm just over here a sound tech... Lol never got to be a musician. Walle and work took my time that I could have used to explore such avenues. Lol nice guitars though! Loving the Amps!
Spray it with what ever color you want, then let it dry, for at least a day or longer then put Vaseline on it then respray your cover let dry and then Wipe the Vaseline off the letters. I have seen ol school painters do it on car emblems.