Changing Plot Area color of Chart using VBA

[tmac98]

I have 2 charts that are created with a macro. But the defaulting colors are not very good. I have tried to change them using all the basic commands that I have found selecting the active chart, plot area and then color index but it doesn't work. I have my code below. The chart is on sheet 4 but the data is on sheet 1.

Any suggestions would be great. Thank you

Tmac

Dim mychtobj As ChartObject
   
    Set mychtobj = Wks4.ChartObjects.Add _
    (Left:=250, Width:=700, Top:=15, Height:=500)
   With mychtobj.Chart
        .ChartType = xlXYScatterLinesNoMarkers
             
        With .SeriesCollection.NewSeries
            .Values = Range(Cells(2, 31), Cells(increment, 31))
            .XValues = Range(Cells(2, 33), Cells(increment, 33))
            .Name = "Chromatogram"
        End With
                
    .Axes(xlCategory).MinimumScale = Wks2.Cells(32, 1)
    .Axes(xlCategory).MaximumScale = Wks2.Cells(33, 1)
    .Axes(xlCategory).MajorUnit = 0.2
    .Axes(xlCategory).MinorUnit = 0.1    
  End With