Hi Kevin,
The following code shows how disable the border around the data labels:
bar.DataLabelStyle.TextStyle.BackplaneStyle.StandardFrameStyle.Visible = false;
bar.DataLabelStyle.TextStyle.BackplaneStyle.FillStyle = new NColorFillStyle(Color.Cyan);
Hope this helps - let us know if you meet any problems.
Best Regards,
Nevron Support Team