Is it possible to change fonts? I have found that fonts (and shadows) have a huge impact on the "wow"-factor of a plot. In fact, I could not help but ask a speaker during a talk what font he used for a particular plot... it just looked great!
I think all charts support setting a custom font style [0]. But: It depends on the backend which fonts you can actually use. Some defaults are always supported [1]. I suppose the cairo backend will load all fonts installed in the system if required, but the diagrams backend only delivers the defaults. For other or custom fonts in diagrams you need a SVG font version of the font and pass it into the backend [2]. Shadows are not supported.