Although the theme that you choose for your presentation applies the default color and font schemes, you can modify the individual elements and change the background to customize the appearance of each slide. The content boxes on the slides are text boxes, which are just another type of Shape.
Use the Sizing handles to resize the text box or the Rotation handle to rotate it, and then drag it to the location you want.
On the Home tab, with the text box selected, click the Quick Styles button, and, in the gallery that appears, click the style you want for the text box.
Click Shape Effects in the gallery that appears, point to the various types of effects, and then click the one you want.
Select the text you want to modify, and use any of the font tools to change the font and its size or color, and to add or remove any emphasis.
Select any paragraphs you want to modify, and use any of the paragraph tools to change the horizontal or vertical alignment, the line spacing, or the text direction; to add or remove bullets or numbering; or to create multiple columns.
On the Design tab, with the slide you want to modify selected, click the Background Styles button, and click Format Background in the gallery to display the Format Background dialog box.
If you want to use a single color, select this option, and specify the color and the degree of transparency you want.
If you want to use a gradient fill, select this option, and specify the colors, the type of gradient, and its direction and angle.
Use these settings if you want to create a customized gradient.
If you want to use a texture or a picture file, select this option, and specify the source you want to use.
Select this check box if you want to use multiple copies (tiling), or clear the check box if you want to use a single copy that’s resized to fit the slide (stretch).
If you chose to use a picture, click the Picture category, and modify the picture as needed.
Click Close to use the settings on the selected slide, or click Apply To All to use the settings on all the slides in your presentation.