i use firefox developer edition. to be fair i spend most of my time in developer tools but i can edit the tools theme in chrome there is an extension that gives custom themes for the browser other than just dark and light
the extension
https://chrome.google.com/webstore/detail/material-devtools-theme-c/jmefikbdhgocdjeejjnnepgnfkkbpgjo
i was hoping if there is a custom dev tools theme like this for firefox
also there was an extension that would convert the chrome extension to firefox add-on but its removed