How to: Change the Color of the Horizontal Axis of a Sparkline
You can change the color of the horizontal axis of a sparkline by using the Color property of the SparkColor object. The following code example iterates through three sparkline groups and sets the color of the horizontal axis equal to the fill color in cell A8. This example requires three sparkline groups starting in cells A2, B2, and C2. Cell A8 must be filled with the color that you want to use for the color of the horizontal axis. This example uses Color property of the Interior object to get the color of cell A8.
Sub AxisColor()
'The sparkline group
Dim oSparkGroup As SparklineGroup
'Loop through the sparkline groups on the sheet
For Each oSparkGroup In Range("A2:C2").SparklineGroups
'Show the axis
oSparkGroup.Axes.Horizontal.Axis.Visible = True
'Set the color of the axis to the color of cell A8
oSparkGroup.Axes.Horizontal.Axis.Color.Color = Range("A8").Interior.Color
Next oSparkGroup
End Sub