You’ll need to dig into the code and rip out the pieces that you want.
The section called /* Minimal settings */ should give you something useful to start with: obsidian-minimal/obsidian.css at master · kepano/obsidian-minimal · GitHub
Alternatively you could go the other direction and modify the Minimal color scheme to match the look you want. e.g. something like Dracula Skin Snippet for @kepano’s Minimal Theme or Share your Minimal Theme screenshots/configuration