The important thing to remember about the font colors is that they should be at high contrast with the background of the presentation slides. For example, use black text on white background and vice versa. This helps improve the readability of text. If you find it difficult to choose the right colors for text to go with the background, look at the templates already available in PowerPoint and get a sense of the appropriate color palette.
PowerPoint 2007 and newer versions have a handy color chart (View> Slide Master> Edit Themes> Colors) which you can use to get the right color combinations for your presentation.
24point0 has a wide range of templates for various business needs available to buy and download. These templates have been designed keeping in mind aesthetics and readability.
Next tip: Keep Font Stylization to a Minimum in PPTs.