This request asks to
increase support for prefer-color-scheme: dark
by accordingly adding styles to the error pages generated by the builtin webserver.

This seems to be in line with earlier changes,
such as taking larger screens into account (as mentioned in #17956),
and complementing the contrast improvement for the phpinfo page (#8893).

In contrast to earlier changes,
i have removed new lines from the styles used on the error pages,
as that seems to be more in line with the rest of the output.

Another contrast with earlier changes, is
using the css function light-dark¹ instead of the prefers-color-scheme used for the phpinfo page.

Aside from that, i have attempted to look for appropriate names for colors and separated the color definitions from the definitions that use them to assign a value to a selector. My hope is that such an approach might ease a future change to a rather consistent coloring scheme within php creations. There seems to be some work done on this, as some styling was moved from ext/standard/info.c to ext/standard/css.c.

On the matter of preferred color schemes, i would like to point out that defaulting to emitting less light to screen viewers seems preferable to bombarding them with light. In other words, it seems to me that being 'lost in the dark' is preferable to being 'blinded by the light'. Hopefully this will be picked up 'en masse' and lead to a default of screens emitting less radiation when a piece of software displays its initial screen.

Visuals

Some (lousy) cropped screenshots.

TL;DR:

Remember Manfred Mann ²

edit: Added visuals section