I have Firefox 91, ClearURLs 1.24.1 with Windows 10 and the options are not saved in the browser. To reproduce the bug, please follow the step: 1 - Install ClearURLs; 2 - Go to about:addons and select the extension ClearURLs; 3 - When ClearURLs is selected, click on options. 4 - Change the badge colour to custom one and click on save & reload addon. That's the first picture in the provided screenshots; 5 - The custom colour is not saved. The options are saved in ClearURLs in this scenario: 1 - Install ClearURLs; 2 - Go to moz-extension://09b00776-fa8a-45d9-b53a-e712aaeb63ee/html/settings.html 3 - Change the badge colour to custom one and click on save & reload addon. That's the second picture in the provided screenshots; 4 - The custom colour is saved properly.