Setting a Transparent Color

The Transparent Color feature can be really useful, but not all pictures support it. It's available for bitmap images (including scans) and for some but not all clip art. For example, suppose you have a scanned photo of your CEO and you want to make the background transparent so it looks like his head is sitting right on the slide. This feature could help you out with that.

Why some clip art images but not others? An image can have only one color set to be transparent, and some clip art images already have their backgrounds set to be transparent. That's why those clips won't work with the Set Transparent Color feature. To check it out, first insert the picture on a slide. Then select the picture, and open the Recolor menu. If the Set Transparent Color option is available, you can set the transparent color by clicking that command, and then clicking the color that you want to make transparent on the picture. If the results are not what you expected, press Ctrl+Z or click the Undo button on the Quick Access Toolbar to choose a different color to be transparent.

If you set a color to transparent in PowerPoint, every instance of that color in that picture will become transparent. So if you have a picture of a man with a white shirt on a white background and choose to make white the transparent color (because you want to drop out the background), the man's shirt becomes transparent, too. Conversely, what looks like one color in a photo is not usually just one color. Think of a blue sky, for example. It probably consists of at least two dozen different shades of blue. If you try to make one of those shades of blue transparent using PowerPoint's transparency tool, you'll probably just end up with splotches of transparent areas.

So what's the solution? The best way to go is to use Alpha channels in a third-party image-editing program to create true transparency and save the image as TIF or PNG. (JPEG format does not support Alpha channels.)