If you’re not ready to eliminate backgrounds all together, but want something very simple, you can create a simple border. It’s dignified, elegant, highly customizable, and you can create it yourself.
First cover the entire slide (or slide master) with a rectangle. Adjust the fill and outline to your liking.
Tip: I gave the rectangle a 10-point line of a slightly darker shade of blue for extra interest.
If you don’t trust your eye to judge centering the next shape, choose View > Grid and Guides and check the Snap Objects to Other Objects check box. (In PowerPoint 2000, choose View > Snap > To Shape.) Use the Title and Content layout.
Next, either choose another rectangle, or for a a gentle curve (and a TV-like look), choose the Rounded Rectangle shape from the Basic Shapes category. Then drag from the top-left corner of the title placeholder to the bottom-right corner of the text placeholder. The shape will snap to the placeholders if you set the Snap to Shape feature.
What’s nice about the rounded rectangle is that you can drag the little yellow diamond to adjust the amount of curvature at the corners.
I gave the rounded rectangle a 6-point line that matched the color of the first rectangle.
Change the fill to white.
Note: If the second shape covers the text placeholders, right-click it and choose Order > Send Backward. Don’t send it to the back, because that will place it behind the first rectangle.
Here’s the result:
Here’s how it looks with some text.
As you can see, it’s very understated. You can download a blank presentation with this background at my Portfolio page.
If you’re interested in more frame ideas, read Geetesh Bajaj’s article, “Create Picture Frames in PowerPoint.” He includes a download of images that look like real picture frames.