If you are a Firefox user and use a dark theme, you can edit your userChrome.css file and add these lines to it for the extension button to more visible:
/* Redirector button for dark Firefox themes */
toolbarbutton#toggle-button--redirectoreinaregilssoncom-redirector[image*="active"]{filter:invert(100%) brightness(600%);}
toolbarbutton#toggle-button--redirectoreinaregilssoncom-redirector[image*="disabled"]{filter:invert(100%) brightness(250%);}If you don't know what the userChrome.css file is or how to edit it, please look it up on Firefox forums instead of asking about it on this repository.