Suppose you are going to do a presentacion using a beamer PDF file and you dont know what size the rooms is, neither how much light there is. Under this circumstances, it would be better to have a "black on white" (the default) version of the presentation as well as a "white on black" version, and decide which one to use once you arrive at the place. Suppose also that you might need to use another computer and copy the PDF file into it.
Is there a simple way to generate a completely inverted version of the beamer PDF presentation??