Fix: use `detect` instead of `select{}.first`

`select` iterates over each object while `detect` stops on first match and so it does not allocates so many string objects and is faster.
Add background color to panel, make usable with dark dev tools themes
Merge pull request #85 from jonlunsford/add-panel-background-color

Add background color to panel, make usable with dark dev tools themes
Merge pull request #80 from divineforest/select-to-detect

Fix: use `detect` instead of `select{}.first`