The text in the data-driven chart templates default to your company's template default for text. The segments default to your company's template color palette. This sometimes means that the segments take on a dark color and so does the text . In order to be able to see the text, it needs to be changed to a lighter color. This can also happen in reverse: light segment and light text. To fix this, just double click on the chart to make it active and then double click on the text you want to change. In the Font menu, you can change the color of the font as well as the background for the numeric values/data labels. Adjust one or both to get the desired results.