This is a simple dark Atom theme.
It uses a small palette of contrasting colours for simplicity:
It has a dark background and uses a number of shades of grey for emphasis.
The different syntax types used in Atom have been set as variables (e.g. storage, keyword, constant etc) to simplify updating the colours in the theme.
This theme could form a good base for other themes - just change the 5 base colours and the background/text colours and the theme should port to most colour combinations.
El Picador is the opening track on Calexico's 2000 album, Hot Rail.
Good catch. Let us know what about this package looks wrong to you, and we'll investigate right away.