Dark theme for Ableton Live 12. In the screenshots the Grid Line Intensity of the Live settings is set to 50%.
On Windows, the path of the Ableton Live theme folder is “C:\ProgramData\Ableton\Live 12\Resources\Themes”.
On Mac, navigate to Ableton Live in your Applications folder, right-click (or ctrl-click) it and select “Show Package Contents”, then go to “Contents/App-Resources/Themes”.
This theme is free. Consider making a contribution if it is useful for you.