battery's case

Hi, I'm new in this forum. I'm spanish and my english is the worst, but I try to explain my problem.

I have two batteries, one of this is black and the other white. I want know if I would convert the white in black and the black in white.

I don't know if the case of batteries are interchangeable, I want remove the batteries' case and replace upside down.

Thank you very much.

EDIT: Can I paint the case? how? Is it easy?

 

You can paint it without any problems, and it will be a lot simpler than opening it up and trying to switch around cells.

Wash the battery casing with strong soap.
Dry it.
Sand it down a little.
Wash with water.
Dry it again, and make sure it's completely dry before proceeding.
Prime it with plastic primer (this step can be skipped).
Apply spray paint, and use a lot of thin layers. Do it five-six times, but really thin.
Let it dry for a day in a warm place.