These legend entries are only visible in certain cases:
- If a chart has any trendlines, they are not visible
- If a chart is a pie or doughnut chart, and it has only one Series or only one set of related series, they are visible
- If a chart has only one series and Series.VaryColorsByPoint is set to true, and it's a type of chart which supports VaryColorsByPoint, they are visible. (Supported charts are all charts which are not Area charts, Surface charts, or filled-in radar charts.)
In all other cases these are not visible.
When data point legend entry fonts are not visible, series legend entries and trendline entries are shown instead.