You’re creating a new or modified chart style with fewer data series than the chart style you started with. That means there are extra data series styles (combinations of color, fill, stroke, and shadow attributes) that aren’t being used. Choose one of the following to determine how these extra data series styles are handled.
All series styles: Uses the series styles you defined and retains the previous styles for the series that you didn’t define. For a new chart style, for example, there are six data series, so if you defined three, then three of the previous styles would be retained.
Only visible series styles: Uses only the series styles you defined. If you apply the chart style to a chart with more series, the series styles repeat.