I was trying to get a grayscale chart and this is the code that worked. Obviously you will want to experiment with different ColorIndex#'s, and yuo may want to use a Mod 12 to repeat every 12 slices. HTH
ActiveChart.SeriesCollection(1).Select
For myPoint = 1 To ActiveChart.SeriesCollection(1).Points.Count
Select Case myPoint Mod 5
Case 0
myColorIndex = 56
Case 1
myColorIndex = 16
Case 2
myColorIndex = 48
Case 3
myColorIndex = 15
Case 4
myColorIndex = 2
End Select
With ActiveChart.SeriesCollection(1).Points(myPoint).Interior
.ColorIndex = myColorIndex
.Pattern = xlSolid
End With
Next myPoint