DataLabels: Setting fill transparency in VBA.

Simple query.

I can change the font colour, style, and fill colour, I just can't seem to change the Transparency.

...(select data labels)...
 
With Selection.Font
.Name = "Calibri"
.Style = "Bold"
.a few more things = whatever
End With
 
With Selection.Interior
.Color = 14136213
.Transparency = 0.5 '<------- Is this incorrect?
End With

Everything else works apart from that Transparency line. It's also worth noting that the transparency can be changed within Excel in the "Format DataLabels" properties window.