looks great but I cant seem to get "Specify a colour" to work, got it to work on one site but idk if its a bug or I am doing it wrong somehow

Easily one of the best add-ons. Turns Firefox into one of the most beautiful browsers in the market.

perfect, just like safari :)

Its the BEST appearance extension ever. Most themes for Firefox are tolerable, not beautiful. This ext provide one of the best colors and borders scheme like mine - Borderless. Its feels really good with different color for each site, the most beautiful Ive seen from themes.
Thank for improving user experience as much as possible (for me ig)

Good extension. Would be cool if Mozilla built this in Firefox

I have no idea how this isn't built into Firefox yet.