You can use colors and pictures as text box backgrounds. If you choose a .gif with a transparent color, the text box background color will show through.
In Page view, select the text box and click the Text Box tab on the Text Properties panel.
In the Color field, select:
Automatic to set the background to the color specified in the Text Object style in Style view.
Transparent to set the background to the background color specified by the parent object of the text box. For example, if a small text box is embedded in a larger text box with a red background, the small text box will also have a red background if Transparent is selected.
Color to select a background color from the Color Picker. The selected color appears in the box to the right of the Color field. To change the color, click the box and select a new color from the Color Picker.
In the Image field, select:
Automatic to set the background to the image specified in the Text Object style in Style view.
None to eliminate the background image.
Browse to select an image from the Open dialog. See Choosing an Image Format. If the picture is smaller than the text box, the browser tiles the image. To change the image, click the Browse button to the right of the field.