Use a color scheme that unifies your theme
Visual presentations must be easy on the eyes. Just as much as you don’t like wearing clothes that have mismatched colors, slides are the same way. Use colors that are consistent with your theme. You can go quirky and fun or formal and subdued. Either way, make sure that you tie up your graphics with your theme. Here is an example:
By placing colors of the theme in the picture itself using shapes and freeform drawing tools, you create a connection between the graphics and the slide color scheme. You may then change the heading text to reflect the color of the graphics so that a further tie-in can be established. This is a good technique to use so as to provide unity in the graphics and the scheme.