Sometimes I get total blackness when I apply lights over lights. But I just keep clicking away with other light sets until one works. Not optimal, but it's the only way I know.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi