When you open a new tab (File/New tab, or Ctrl + T) you get a blank tab.
If blank is too much for you, try adding some color and style to the blank page.
Just add this code to your userContent.css file located in your profile folder to add a light Firefox icon to the bottom right of the blank page.
As you can see in the linked code, the image is embeded as a data URI. You can use your favorite image replacing the data URI with your favorite image:
- Visit Ian Hickson’s data: URI kitchen,
- Check the base64 check box
- Upload your image
- Replace the data: URI in the linked code with the generated link