Good old latex exterior paint will work if you mount it along the house eaves. If you put it on a tower, a mast, or in a place that can be a challenge to reach, paint it with epoxy or CARC paints. They'll last a decade or longer without maintenance if done with epoxy or CARC paints.
Yep, metallic paints will cause problems.
Mainly watch aluminum, silver and some gold colored paints as they can all carry some metal in the paint.
When I've needed to do this, I'd paint a hunk of plastic or something kind of hard and non-conductive. Let the paint cure as long as needed and then probe it with a DMM with the probes stuck well into the paint but spaced close to one another. If the paint is conductive at all, you will usually see a reading. Those are the ones I've stayed away from
In general, I've always used one of the rustoleum primers like the standard grey primer they sell. Those have always proven to be non-conductive plus the give a nice and durable coating plus usually dry very fast. Just mask off any connection points are tuning devices like gamma matches found on some yagis as some of those require metal contact to tune properly.
You may also want to make sure you are using an aluminum compatible paint if painting aluminum. As for as aluminum goes, I'd probably never paint an aluminum vertical that tunes by altering the element lengths where they insert to the next larger of smaller element size and slide up or down for tuning. You don't want paint in there.