I agree something cheap and simple.
Flat black would be best for the contrast I think.
Especially since I need all the help I can get as my eyes are not quite what they used to be.
Besides they are targets and are going to get the sh-t shot out of them.
John Deere has a Medium Black which is real tough but Tremclad or Rustoleum would be the easiest to find.
Walmart and Princess Auto both sell a cheaper flat black spray bomb that works well.
Not having any luck finding the contact info I mentioned, will keep looking.
Grunt