Style utilities, templates, and defaults for syntax highlighting widgets.
Convert a hex color to rgb integer tuple.
Check whether a color is ‘dark’.
Currently, this is simply whether the luminance is <50%
Guess whether the background of the style with name ‘stylename’ counts as ‘dark’.
Construct the keys to be used building the base stylesheet from a templatee.
Use one of the base templates, and set bg/fg/select colors.