Series.Format.Fill.Transparency property not applying formatting - excel

Question

I have a chart in which I create a number of new series for using the Chart.SeriesCollection.NewSeries method, there after I immediately format each series. All formatting seems to work (marker size/style/colour) bar marker transparency which I set via the Series.Format.Fill.Transparency property.
I have seen people using the selection method to set series marker transparency as per below:
Set GraphSeries.Absolute.ErraticErrors = AbsChart.SeriesCollection.NewSeries
With GraphSeries.Absolute.ErraticErrors
.Name = "ErraticSeries"
.MarkerSize = CommonMarkerSize
.MarkerBackgroundColorIndex = Graph.XY.Formatting.MarkerFillColour.ErraticErrors
.MarkerForegroundColor = Graph.XY.Formatting.MarkerLineColur.ErraticErrors
.Select
Selection.Format.Fill.Transparency = CommonMarkerTrans
.Format.Line.Visible = msoFalse
End With
After trying and troubleshooting the above method, it seems when the marker transparency is set, the marker background colour can be seen to change value rather than the transparency which remains at its initial value, strange? Based on this finding, I reverted back to Series.Format.Fill.Transparency = CommonMarkerTrans and viewed this property in the watch window while setting it to CommonMarkerTransand observed no change to the initial value of Series.Format.Fill.Transparency (-2.147484E+09), also strange?
Seems that the Series.Format.Fill.Transparency property is not changing from its intial value when trying to set it to CommonMarkerTransvia Series.Format.Fill.Transparency = CommonMarkerTrans
Note: CommonMarkerTrans= 0.9 as single
Anyone have any ideas why this is? I'm really stumped here, could it be related to the ordering in which I am setting the marker formatting?
Below shows a snippet of code to provide context. The code creates an 'empty' chart series and then applies various formatting, such as marker size, and then sets the series X and Y values from data stored in two separate arrays.
Set GraphSeries.Absolute.ErraticErrors = AbsChart.SeriesCollection.NewSeries
With GraphSeries.Absolute.ErraticErrors
.Name = "ErraticSeries"
.MarkerSize = CommonMarkerSize
.Format.Fill.Transparency = CommonMarkerTrans
.MarkerBackgroundColorIndex = Graph.XY.Formatting.MarkerFillColour.ErraticErrors
.MarkerForegroundColor = Graph.XY.Formatting.MarkerLineColur.ErraticErrors
.Format.Line.Visible = msoFalse
End With
RelOrAbsChart.SeriesCollection(SeriesName.ErraticSeries).XValues = XAxisRelOrAbs.ErraticSeries
RelOrAbsChart.SeriesCollection(SeriesName.ErraticSeries).Values = YAxisRelOrAbs.ErraticSeries

Answer 1

Seems I may have solved this. For some reason you must use the following properties to set for/background colour of series markers if you want to use Fromat.Fill. Transparency to set the marker Transparency
Series.Format.Fill.ForeColor.RGB = RGB(R,G,B)
Series.Format.Fill.BackColor.RGB = RGB(R,G,B)
And not
Series.MarkerBackgroundColor = RGB(R,G,B)
Series.MarkerForegroundColor = RGB(R,G,B)
Not sure why this is the case, seems confusing to have two separate properties to set Marker for/background colour and not be able to set transparency for both.
Why would you need two separate and mutually exclusive properties for the same thing? For clarity, maybe someone could clear this up or correct my understanding?
Functioning code which now sets colour and transparency correctly:
Set GraphSeries.Absolute.ErraticErrors = AbsChart.SeriesCollection.NewSeries
With GraphSeries.Absolute.ErraticErrors
.Name = "ErraticSeries"
.MarkerSize = CommonMarkerSize
.MarkerStyle = xlMarkerStyleCircle
With .Format.Fill
.Visible = msoTrue
.ForeColor.RGB = Graph.XY.Formatting.MarkerFillColour.ErraticErrors
.BackColor.RGB = Graph.XY.Formatting.MarkerLineColur.ErraticErrors
.Transparency = CommonMarkerTrans
.Visible = msoTrue
End With
End with