This is the source repository for FontWithASyntaxHighlighter font. See examples and full explanation at https://blog.glyphdrawing.club/font-with-built-in-syntax-highlighting/.
The Night Owl and Light Owl color themes are based on the Night Owl theme and built with fontmake.
In order to create your own color theme, edit the color palettes in lines 112-120 of the FontWithASyntaxHighlighter.glyphs file and build the font with fontmake.
FontWithASyntaxHighlighter is modified from (MonaSpace). Licence is SIL open font license v1.1.