Favorite Icons (favicons) are personalized icons that accompany web page titles.
FedWiki has created colorful "flags" as that help identify the owner of different FedWiki sites. Since this is a federation of sites these are quite useful for knowing who is who in the neighborhood.
One has considerable choice in the color and shading of your favorite flag icons. See About Flagmatic Plugin. Also see You're New Here.
When you click on a new color it is assigned to your site. > Unfortunately your browser has stored the old one and will not show the new one in the browser tabs until you clear the cookies. Of course that deletes the automatic memory of recently visited sites.