MarkerForegroundColorIndex Property [Excel 2003 VBA Language Reference]
Returns or sets the marker foreground color as an index into the current color palette, or as one of the following XlColorIndex constants: xlColorIndexAutomatic or xlColorIndexNone. Applies only to line, scatter, and radar charts. Read/write Long.
The following illustration shows the color-index values in the default color palette.
This example sets the marker background and foreground colors for the second point in series one in Chart1.
With Charts("Chart1").SeriesCollection(1).Points(2) .MarkerBackgroundColorIndex = 4 'green .MarkerForegroundColorIndex = 3 'red End With