To override this (or any other) theme in your personal config file, please follow the guide in the color theme documentation. This is handy for small tweaks to the theme without having to fork and ...
However, we observed that out of all customizable things, people really like trying out new themes. Some do it just for fun, and others use it to get rid of pre-installed custom skins. Whatever ...
Be aware that this theme might do things that are not supported by upstream Firefox. If you face an issue while using this theme, report it here first or test if it is reproducible in vanilla Firefox.