[dheera]

Unfortunately Chrome doesn't granularize it any further. Basically all it needs to do is inject some CSS, and in Chrome permission-speak that is covered under the umbrella of "read and change all your data".

The source is however available so you could inspect it for yourself and install from source:

https://github.com/darkreader/darkreader

[Reelin]

> all it needs to do is inject some CSS

Actually I believe the default mode analyzes the page contents in an attempt to provide a better end result.