Firefox addon(Now support firefox 57+): https://addons.mozilla.org/firefox/addon/darker-bg-brighter-font Google chrome extension: https://chrome.google.com/webstore/detail/mdolidbiejfnaejdoagjacapnichoccj Features: Darken background color and brighten font color Decrease "image and background image" brightness Adjustable "change style speed" Enlarge font size (default is trun off) Setting page for every domain (click the addon button when user browsing) Global setting page for all domain (in about:addons => this addon options) After changing options, users need reload page, let option setting apply to page. If this addon have bad effect in particular page, go to that page and click the addon button, set option off, make function just don't use in that current domain. Because browser restriction, addon can not work in those page: "about:*" "https://addons.mozilla.org" "moz-extension://*" Open source in github: https://github.com/zero0evolution/darker-background-brighter-font-webextension/ User can report bug in github issues: https://github.com/zero0evolution/darker-background-brighter-font-webextension/issues Support developer: https://www.paypal.me/zero0evolution/0USD