We use [Sass Map](https://github.com/netguru/help/blob/add_description_to_topics/app/assets/stylesheets/settings/_variables.scss#L1) for defining colors. We also use shorthand for syntax:
```scss
color: color('base');
```
Currently we don't have <code>black</code> color and I don't feel like we should add it. Please use existing one :)