To set the background of the quiz, click Player Template > Background, the background of the quiz can be filled with a color or an image, set the font color, as well as set the transparency of the background.

Picture: A picture can be added as the background image.
More options: Choose this command to open the Background Settings dialog box.
Fill style: Selecting Solid, you can click More Colors to open the Color Panel, and select a color to fill the background. Selecting Picture, you can click Browse to find a picture on your computer as the background image, and then choose a position of the image.
Font color: Select a color for Quiz Title.
Opacity: To specify how much you can see through the background, move the Opacity slider or enter a number in the box next to the slider. You can vary the percentage of transparency from 0% (fully transparent) to 100% (fully opaque).