I've tried different dark themes, but this one is the very best, to my taste anyway

Finally, a good dark theme that makes it easier to distinguish between active and inactive tabs in Firefox Proton.

Dracula Theme is hands-down the single best dark color theme available, not only because of the color palette, but because it is available for a huge array of applications on many operating systems. It enables a consistent and visually pleasing theme across my entire system on Linux and macos (and probably wintendo too, were I to use that).