Sadly enough Sandyriver, both dogs have their tags on snap rings and aren't on them all day.
I had a bunch of old lanyards lying around and I tore off the old ID tags and kept the rings specifically for their tags. I found it easier to take them (tags) on & off between home collars and walking collars.
The metal hasn't affected our Springer, Gryphon and he has a neck full of white fur, it's just affecting our white setter, Mollie.