Indico UI
Atom based on Predawn UI.
A dark UI theme forInstallation
Either, search for it in the Packages section in you Atom settings tab. Or from the command-line run:
apm install predawn-ui
Also, view on Atom.io at http://atom.io/packages/indico-ui
Syntax Theme
You should also install the accompanying syntax theme, called indico-syntax.