Different favicon if the browser is using dark mode
Chrome is still implementing (prefers-color-scheme: dark), so the jury’s still out. https://crbug.com/889087. In Chrome 76 with --enable-blink-features=MediaQueryPrefersColorScheme, this correctly sets the icon when the page is loaded, but does not respond dynamically to changes in dark mode.
Safari adds a grey background to dark icons in dark mode (for example, Wikimedia Foundation (https://wikimediafoundation.org/), Github (https://github.com/)), so this workaround isn't necessary for legibil...