The Mozilla team has rolled out a new Test Pilot experiment that lets users customize some of their browser's user interface element colors.
This would then install a second add-on that would grant users access to a dashboard where they can customize the browser's UI colors.
Not all the browser can be customized, but only the top section containing the menu bar, tab bar, address bar, and bookmarks bar. The Firefox settings section will remain as it was before.
For users getting started with the new "Color" dashboard, there are 24 pre-built browser themes to get them started.
The Color experiment comes just as Mozilla has retired support for "full themes" with the release of Firefox 57. The browser now supports only "lightweight themes," known as Personas.
But Personas only allow the user to change the top section's background with a custom image. The Color experiment takes Personas to a new level by allowing users to control background colors, highlights, and text colors as well.
Either way, Color is nowhere near the customizability of the old Firefox "full themes," which also allowed theme developers to adjust tab size, tab width, tab and toolbar positions, and many other options.
Besides the Color experiment, Mozilla also launched a second experiment. This second Test Pilot feature —named "Side View"— lets users view two web pages side by side inside the main Firefox window.
The Side View feature takes advantage of a native Firefox feature called the sidebar panel. Normally, Firefox uses this sidebar to show bookmarks, browser history, or synced tabs across devices, but unbeknownst to most, the sidebar panel can also be used to view web pages.
Some clever Firefox users were already using this feature to view pages side by side for a long long time. The Side View Test Pilot experiment makes sending pages to the sidebar panel much easier, with the click of a menu option or toolbar button.