I’ve reproduced the problem with the colors of the chart series and added a ticket with ID SLIDESNET-43156 to our issue tracking system. We apologize for any inconvenience. Our development team will investigate this case. You will be notified when the issue is resolved.
You could try changing colors for data points as shown below
var dataPoints = chart.ChartData.Series[0].DataPoints;
dataPoints[0].Format.Fill.FillType = FillType.Solid;
dataPoints[0].Format.Fill.SolidFillColor.Color = Color.Red;
but I have not found a way to match the colors of data points with the legend colors. Therefore, I added a ticket with ID SLIDESNET-43157 to our issue tracking system. Our developers will consider implementing such a feature. We will inform you of any progress.
The issues you have found earlier (filed as SLIDESNET-43156) have been fixed in Aspose.Slides for .NET 22.6 (ZIP, MSI).
You can check all fixes on the Release Notes page.
You can also find the latest version of our library on the Product Download page.