On the Formatting toolbar,
click Design ,
and in the task pane, click Color Schemes.
On the Slides tab, click a slide to display the color schemes in the task pane.
If you have applied more than one design template in the presentation and you want to see all the available color schemes, press CTRL to click a slide from each design group.
Note A presentation must contain at least one color scheme, so you cannot delete the last scheme.