Applications :: Changing Slide Background And Themes In Powerpoint Or Keynote

So I have several CME Conference Lectures (slides made in PPT). Unfortunately, I guess these presenters love color, and so all slides are in a blue background with white text or some variation thereof. Personally, I like to have a print out of the slides when I am reading/preparing for my future cases. etc. and so I physically print these slides out. Unfortunately, the unnecessary background color is an unnecessary burden on my printer, and so I was wondering how I can change the the background and text in one shot so I don't have print out the unnecessary color.

I have tried trying to change the background from within powerpoint, but because the text is often in white, this causes the text to "disappear" on a white background. The only way to get the text back is to change the text color on a slide by slide basis. This is fine if the presentations are short, but most of these presentations are 200+ slides.

I was hoping there is some trick either in powerpoint or keynote to be able to change slide themes (such that background and text can change in one shot).