This is the a UI Theme forked off https://github.com/jesseweed/seti-ui
This fork is black UI changed a bit of seti-ui
The easiest way to install Seti is to do as follows:
themesbutton to search.
Alternatively you can use the Atom Package Manager:
apm install seti-black-ui
Good catch. Let us know what about this package looks wrong to you, and we'll investigate right away.