In painting, you have unlimited power. You have the ability to move mountains. You can bend rivers. But when I get home, the only thing I have power over, is the garbage.
If you did this with yellow, and you went over it with blue, you would end up with a .. with a translucent... green. And it's gorgeous. It is GORGEOUS.
If you did this with blue, and you went over it with yellow, you would end up with a nice green sky. And that's not the thing we are looking for.