Man, I wish presenters at conferences would learn this. Really, just that they'd learn that the contrast range on their laptop is huge compared to the contrast

Man, I wish presenters at conferences would learn this. Really, just that they'd learn that the contrast range on their laptop is huge compared to the contrast range on the projector that everyone else is looking at, especially when you're far from the screen. Surprisingly (to me) I saw really-light-blue-text-on-white as well as the hipster-dark-colors-on-black at the last conference I was at. Neither was legible...