Firefox 40 has some theme fixes for Windows 10. Please update and see if there are any problems still present.
Sorry, my bad on those two.
https://addons.mozilla.org/en-US/firefox/addon/team-7/
https://addons.mozilla.org/en-US/firefox/addon/numark-ns-7/
https://addons.mozilla.org/en-US/firefox/addon/fallout-4/
https://addons.mozilla.org/en-US/firefox/addon/peace-love-hippie/
https://addons.mozilla.org/en-US/firefox/addon/akatsuki-no-yona/
https://addons.mozilla.org/en-US/firefox/addon/tigrefox/
https://addons.mozilla.org/en-US/firefox/addon/prison-school/
https://addons.mozilla.org/en-US/firefox/addon/mousetrap/
https://addons.mozilla.org/en-US/firefox/addon/hello-kitty-wmo-01
https://addons.mozilla.org/en-US/firefox/addon/earth-eleven-go-all-stars/