It sounds like you haven't created a custom style. You can do that at the "Your Styles" area. When you decide on a name and hit "create", you'll be taken to a new page to edit the style you just created. Set the "Layout Layer" to "Tabula Rasa". Set "Theme" to your custom theme layer (the one you named "favicon"). Set "Wizard" to "Auto-generated Customizations". And then save. You'll be taken to the "Your Styles" area again and you'll see the style you just made. Hit the use button next to it and it should all work.