Brackets comes with two themes installed, "Backets Light (Default)" and "Backets Dark". To see them, go to View | Themes...
I really like the "Brackets Dark" theme and I'd like to create a duplicate syntax theme of it for GitHub's Atom editor. I'm trying to locate these two default themes. Since they aren't third party themes, they aren't in the extensions folder. My question is where can I locate the "Brackets Dark" theme?
You can find the main.less and package.json for the Brackets Dark theme here (on Mac):
/Applications/Brackets.app/Contents/www/extensions/default/DarkTheme
to get to the Contents folder, just right click on the application and hit "Show Package Contents"