Problem

We are looking to deploy pydata-sphinx-theme on our docs (astropy/astropy#14867). The theme has a nifty light/dark mode toggle. Very quickly it is apparent that the generate plot using matplotlib's .. plot:: directive stays in light mode no matter what. The result could be pretty jarring.

Proposed solution

Would be nice for the .. plot:: directive to follow light/dark mode. Though you might want it as opt-in just in case some users do not want that, especially if you decide to use the CSS color-inversion trick that scipy does in https://github.com/scipy/scipy/blob/c1b803b66a3e9f0416f3feafc6d4cf24d2ec98e2/doc/source/_static/scipy.css#L133 .

Thank to @ksunden for pointing that out to me!