It amazes me the color choices I see presenters make for their slides. Let me give you a couple of recent examples. The first is a presenter who chose a blue background for their slides. Not a bad choice at all, in fact it is one of the colors that works well and is quite popular. Where this presenter made the mistake is in selecting a text emphasis color. The regular text was in white (good choice), but the most important text, the words he wanted the audience to pay most attention to were in red (aaaaahhhhhh!). When projected, I doubt even half the audience could see, let alone read, the text in red, which left them with the only readable text being the less important words out of context. The second example was a presenter who used solid black as the background, but made poor color choices elsewhere. The first mistake was in using a graphic in the top left corner that had bright blue, red and yellow squares in it. Even with white text, your eyes were only drawn to this bright splash of color and away from anything else on the slide. The second mistake was the choice of text color on the diagrams - the presenter chose medium grey. Almost impossible to see when projected. When selecting colors, make sure that people will be able to distinguish between them. Select colors that have enough contrast so that the text stands on top of the background.