I have observed the requirements shared by you and like to share that Aspose.Slides allows you to work with scatter charts and its entities including changing the marker color, series line colors and symbols for markers. I request you to please visit the documentation link 1 and documentation link2 to serve the purpose in this regard. Please share, if I may help you further in this regard.
//Changing the chart series markerseries.Marker.Size = 20;series.Marker.Symbol = MarkerStyleType.Circle;series.Marker.Format.Fill.FillType = FillType.Solid;series.Marker.Format.Fill.SolidFillColor.Color = Color.Orange;series.Marker.Format.Line.FillFormat.FillType = FillType.Solid;series.Marker.Format.Line.FillFormat.SolidFillColor.Color = Color.Green;series.Marker.Format.Line.Width=2.0;
Perfect thank you.