Francis, I thought about repainting mine sometime back, but I decided to simply leave it as-is. Normally, as you may know, I tend to leave signals I acquire in their original condition.
While I agree that dark olive green is a nice color, if I repaint the housing, I feel that I'd remove all that original exposure to the environment it was once in.
Personally, I'd leave it as-is. Though it is your Ruleta, and you could do whatever you want to it as you please. :-)