Identify many instances of GitLab servers with a nice looking color
Allow Pro users to change the border of the navigation and other colors too signify which server they are looking at when multiple servers are being used.
It is a common complaint that people who manage many instances of GitLab want to tell them apart. They used to use the sidebar for this but we took this away. I posit we make a small by nice color customization for user who have this need. It is not art for arts sake. It is visual for identification sake.
I also believe we should customize the favicon more to show this line in some way. Maybe add some nice shades of a color to the tanuki. It would be subtle but recognizable enough.
