We've found that the best fonts that work for digital signage are simple ones, and sans serif ones top that list. This doesn't mean you can't go using your favorite Script Styles or Decorative Style fonts, it just means you need to choose wisely. If your brand allows, reserve those fonts for large titles and subtitles and keep your body copy limited to a simple font that will allow people to read large chunks of information easily.
Two to three different types of fonts on your screen at the same time is more than enough. Mixing and matching too many fonts can make your screen feel unorganized, unprofessional and hard to read. Stick to a collection of a few simple fonts and you should be good to go.
Most screens are viewed from afar. Font size needs to be large enough for people to view and read from a distance. Presenting the content in a way that visually conveys where to look, and in what sequence, helps guide the eye. Titles, subtitles and body copy all have their place on the screen.
Color can bring attention to something you want people to read. Highlighting a word in a sentence can help reinforce the importance of that word. Too much color on the other hand can be distracting and the wrong color can be downright impossible to read. Choose wisely and be sure to select a color that's already in your signage or part of your brand.