Create a full-screen picture, texture, or effect for the background

For a texture, click the Texture tab.

For a picture, click the Picture tab. The picture will be automatically sized to fill the entire background of the slide. If the result is not what you desire, use the procedure: Create a background with a picture, logo, or other objects

For a pattern or gradient, click the Pattern or Gradient tab. The important thing to be careful about is which colors you choose. We recommend highly that you do not use any "first row" colors, which are linked to the color scheme. Instead, use colors on the second row, which are custom colors or, if you don't see the color you want on the second row, click More Colors and specify the color you want.

Most likely, the color scheme is not correct--return to step 2

It might be that there are objects on the slide that have been "sent to back" that are blocking the view of the actual background. Delete any objects that are interfering with the background of the slide master.