Lousy oven and oven operator.
Turned/swapped trays at 5 minutes.
At 10 minutes they were still all white.
Set timer for three minutes (I thought), but had an extra zero in it (30:00).
I was wondering why the alarm hadn't gone off, went to check. and that is what they looked like.
I need to discipline myself to stay right there and turn/swap trays every 3-4 minutes.