Gradients make effective simple backgrounds. Unfortunately, PowerPoint only allows two colors in a gradient and gives you little control over where the colors change. However, you can use an easy trick to make multi-color gradients and add control over where the colors change as well.

You can combine rectangles, each with a slightly different gradient to create the effect of one larger, multi-colored gradient. For a seamless look, each rectangle must start with the same color as the ending color of its adjacent rectangle. Follow these steps:

Decide on the colors you want and where you want them to change. Remember that shading styles (such as horizontal) have two to four variants.

Create a series of rectangle that touch each other and completely cover a slide, as shown here. Right-click the top rectangle and choose Format AutoShape. On the Colors and Lines tab, choose None from the Color drop-down list of the Line section.

From the Color drop-down list of the Fill section, choose Fill Effects and then click the Gradient tab. Choose the Two colors option, then select the colors you want, choose a shading style and a variant. Remember which color fills the bottom of the rectangle.

Repeat steps 3 and 4 for the next rectangle(s), making sure that the color of the top part of the rectangle exactly matches the bottommost color of the previous rectangle. Here is one possible result, using two shades of gray. Notice that using light gray (or white) gives the impression of a highlight and thus creates a 3D effect, as if the slide has been curled at the top.