AutoCad 3D :: Render Is Always Going To Black And White?

I was doing a machina at autocad 12 and when i was in rendering options I must have do something wrong, and now, when I try to render anything, the render goes on black and white. This machine is black, silver and transparent (plastic, metal and glass) and the metal goes on grey, the plastic (wich is black) goes on white and the glass disappears.

I tried to open another windows, make boxes with black plastic and another with glass, and the black turns on grey or white..