I am trying to create a single bold DataLabel on a chart using SpreadsheetGear. I can set the number to be Green using the code below:
DataLabels(0).NumberFormat = "[Green]###,###,##0"
But when I attempt to set a property of the Font nothing appears to happen. I have tried the below with no success.
DataLabels(0).Font.Bold = True
The code you have should work. If you have other code that is manipulating the series that the data labels belong to, try putting the line
DataLabels(0).Font.Bold = True
after any such code.