Why not do the exact opposite what the presentation design establishment is trying to teach you - on purpose?
Dave McClure is an investor in startups that does exactly that. Random colors, bullet points galore, "love that clip art", arbitrarily placed images, and some pretty rough language. Kicking the presentation etiquette. Building businesses is all about getting your hands dirty, passion & energy, and ignoring slick packaging. It's the substance that matters.
Here is a recent presentation (some strong language):
The resulting presentation is actually pretty good. I am sure the "show" on the London stage was great. And through reading the slides I get the main point about feature focus. If you have Dave's substance and confidence, there is nothing holding you back to deliver a presentation like this.
Another example of a presentation by Dave: how to pitch to a VC (strong language)