The Preparing PDF page should match the dark theme as the rest of the UI
Actual result
White screen that flashes in my face
Environment
SYSTEM INFO:
Obsidian version: v1.7.7
Installer version: v1.5.12
Operating system: Windows 10 Pro 10.0.19045
Login status: not logged in
Language: en
Insider build toggle: off
Live preview: on
Base theme: adapt to system
Community theme: none
Snippets enabled: 0
Restricted mode: on
PDF is tied to printing, you don’t want to waste all your black ink just to “paint” black pages.
Probably you could buy black paper and try to print white letters on it, if something like white ink exists. And even if you could get white ink, you would need some special ink.
If you want just a PDF, then adding some rules to CSS print media should give you black pages.