An image can have the following effects or adjustments applied to it:
Black and White
To add any one, or several, of these effects to a photo or clipart, simply select the image and click on the Effects palette in the left vertical toolbar.
Choose from the variety of options available (listed above) and note that the effect will take place immediately so you can see whether you want to keep it or not. If you want to undo the effect you just applied, just click on the Undo button at the top of the screen.