How to set iPhone background to black?

[Johanovski]

Hi there!

I'm working in an OpenGL project where I use a UIView as the drawing layer. The UIView fits the screen (that's 320 x 480 in portrait mode), but I want to simulate a trembling effect, so I've thought the best way is to move the whole UIView rather than shaking each OpenGL object independently. The effect is really great and it works perfectly, however under the UIView there is white color, so the effect isn't as good as it should be if the background was black... The UIView is black, of course, but then I move the UIView what I've seen under it is "nothing", so can I set "nothing"'s color to black?

Thanks in advance!