Select type of background you want:
- Use background color:
  Use one color only, set in Colors preferences.
- Transparant:
  Background of output window is transparant,
  and desktop background is visible through it.
- Background from file:
  Load an image from a given file as background.
  Method:
  - Tile:
    Place image side by side to fill the output window
    if it is smaller.
  - Fit to window:
    Scale the image so it fills the entire output window.

- Tint background:
  Put a tint over the background or transparency, use
  Red, Green & Blue slides to select the color.
