This is from freestylephoto. I recently discovered how much better amber safelighting is than red safelighting. It's a lot more comfortable, and it seems to be fine with my paper. I saw this quote from freestylephoto's safelight page and it doesn't make any sense to me. I'm not sure why you would use both red and amber at the same time, but I don't see why a blend of them would be worse than either one by itself, if the total output was the same.