I am getting peculiar green/blue shiny stains on the blades of my Dansk stainless. Some of it is 40 years old, some of it is less than 2 years, but all the knives seem affected. We moved this summer, but only 4 blocks away, so I doubt the water is different, I'm using the same detergent, and we bought the same dishwasher as at the old house. Any ideas on removing it? The older flatware has been dishwasher washed since I've had it. What gives?