A few years back, I started a new theme that I call “bland”. I kept it at just pure black on pure white, keywords bold, comments italic for a week. After that,

A few years back, I started a new theme that I call “bland”. I kept it at just pure black on pure white, keywords bold, comments italic for a week. After that, I agreed that some colour was useful, so I made strings red, numbers blue and comments green. All nice and high contrast. Since then I’ve added a little more from time to time, e.g. lifetimes in Rust are italic red, and attributes and macros in Rust code were orange for a few months but are now just italic black (though I still use orange for macro_rules $variables), but I’ve kept it all deliberately minimal and ultra-high contrast. I use the same styling (except for the background colour) on my website. I made a bland-dark somewhere along the way that I very occasionally use, also used on my website. I should probably try something radically different again in another different direction soon. There are generally somewhat better options available for semantic highlighting now than there were five or ten years ago.