I look down into the porcelain, and saw a colour you don't want to see there - red! Red as in blood, red as in danger, red as in oh my god, what's happening down where the sun doesn't shine?
Then I thought, ladysolly has been giving me baby beetroots in my salad recently, and my fingers have been stained that same colour.
So I'm going to avoid beetroot for a few days, and if the red goes away, I'll know it was only the beetroot.
... update ...
After a couple of days of my non-beetroot diet, the red vanished, and everything is nice and brown again. So no problem!