Every master slide has a background that matches the other slides in its theme. It's usually a good idea to stick with these matching slide backgrounds for the sake of maintaining a consistent appearance throughout your slideshow. However, you may want to set off different segments of a presentation with different themes, or sometimes create a slide that diverges completely from the status quo.
To change the slide background, open the Slide Inspector and click the Appearance tab. The bottom section of the Inspector controls the slide background. Most slides that are part of a theme use an image fill background. Click the upper popup menu in the Background section and choose one of the following background fill types:
None . As you might expect, this choice removes the background entirely, rendering the background white. This is as close as you can get to the retina -burning white screen of a jammed slide projector. Unless you're going to be filling this white space with a lot of text or objects, it's probably not a very good choice. Unlike the printed page, in the projection business white space is not your friend.
Color Fill . If you choose this, a color well appears in the inspector. Click the color well to summon the Color Picker, where you can choose a solid color for the background. Master slides that use photo cutouts use a color fill for the background that's behind the cutout layer. Details on Section 4.4.2.
Gradient Fill . Choose this style fill to create a gradienta gradual blending from one color into another. Keynote displays two color wells in the Inspector in order to choose those two colors. In addition, you can control the angle of the shifting colors with the Angle knob, the direction arrows, or by typing an angle directly into the angle measurement box. See Section 4.4.2 for the details.
Image Fill . Choose this option if you want a photograph or other image for a slide background. Image Fill is probably selected if you're working on a slide that's part of a themethe theme background is an image. Keynote displays an image well at the bottom of the Inspector. To use your own image for a background, drag an image file from your hard drive or from the Media Browser into the image well, or click Choose and select an image file from the Open dialog box that appears.
The lower pop-up menu in the Background section of the Slide Inspector determines how Keynote displays your chosen image in the background. The various scaling options let you choose to display the picture at its original size , scaled to just fit the background, scaled and cropped to fill the background, stretched to fill the background, orif it's a very small originaltiled over the background. See Section 4.4.4 for more details on how image fills work.
Tinted Image Fill . This final choice in the background fill menu is a variation on Image Fill in which you can blend a color with the image in order to, for example, make a rosy sunrise picture even rosier. This is also the trick to displaying a background image at a reduced density by tinting it with white. You'll find details on Section 4.4.5.