' Set the mimimum color Me.ultraChart1.ColorModel.ColorBegin = System.Drawing.Color.Blue ' Set the maximum color Me.ultraChart1.ColorModel.ColorEnd = System.Drawing.Color.Red myseries.Points.Add(new TreeMapDataPoint(12, 34, "item1", False)) ' The second arg represents the color value ' Set the leaf node color to blue myseries.Points[0].Points.Add(new TreeMapDataPoint(20, 0, "FirstChildOfItem1",False)) ' Set the leaf node color to purple (half way between blue and red myseries.Points[0].Points.Add(new TreeMapDataPoint(20, 5, "SecondChildOfItem1", False)) ' Set the leaf node color to red myseries.Points[0].Points.Add(new TreeMapDataPoint(20, 10, "ThirdChildOfItem1", False)) Me.ultraChart1.Series.Add(myseries)