I think that for most apps, this is the wrong approach to use by default, as it will produce something that will always look out of place. I think you’re genera

I think that for most apps, this is the wrong approach to use by default, as it will produce something that will always look out of place. I think you’re generally better to default to just using the five or so dependable colours, and not try to be cleverer. You may be able to mitigate the damage by checking what the default background and foreground colours are (and perhaps other of the top 16 colours, to get a feel for the style of theme) and choosing colours that will match as closely as possible while still supporting the flexibility you want, but that would be a fair bit of work to do well. Terminals are not the web. As an extensive user of both terminal and web, and often a heavy customiser of both, I would strongly prefer that by default you prefer to fit in, even though it limits your degree of expression.