Currently, Firefox only supports colorful Favicons, because the Web has no standardized Format for monochrome Favicons.
The Website Vendors’ colorization of Favicons clashes with the Users’ colorization of Tab Groups, so i would love to switch to monochrome Favicons, inspired by monochrome App Icons in Android.
There is an easy half Fix in the Form of a Firefox Add-on named Desaturate Favicons.
But it’s only a half Fix because all it can do is forcing the original colorful Favicons to become greyscale.
This means that Designers can’t make monochrome Favicons that use the Strengths of that Format,
and there’s no Way to make sure that all monochrome Favicons have the same Lightness Contrast against their Background.
Long-Term, Web Browsers should have first-Class Support for monochrome Favicons, for a clean Aesthetic and less Distraction while the User chooses their own Colors for organizing Tabs and Bookmarks.
Even better if Websites could index an Outline Design and a Fill Design for monochrome Favicons, to better match the Design of different Web Browsers.
