I have been pondering something the last few days. When I was a kid and Dad would grill burgers, they would almost always turn out a reddish color. Since growing up and grilling my own meats, this has not been my experience. I have not noticed it at other people's cookouts, either.
Dad is no longer with us, so I cannot discuss with him. Anybody else have any ideas? If memory serves, he would use Kingsford brand charcoal briquettes and petroleum-based starter fluid. That is indeed different than my supplies, but other people use the same stuff with regular colored burgers.
As far as the meat, it was just whatever was found in the small town grocery store, probably ground chuck. Seasoning was generally nothing more than salt, pepper, and garlic. Oh, and they were always cooked quite a bit more done than I prefer, but still wish I could eat one with him today.