Solved! just have to change Selection.Tables(1) to oTabl
THANKS!!

Code:
Sub ScratchMacro()
'A basic Word macro coded by Greg Maxey, http://gregmaxey.com/word_tips.html, 7/20/2017
Dim oTbl As Table
Dim oCell As Cell
For Each oTbl In ActiveDocument.Tables
For Each oCell In oTbl.Range.Cells
If Not oCell.Borders(wdBorderTop).Color = RGB(0, 128, 0) Then
oCell.Borders(wdBorderTop).Color = RGB(0, 128, 0)
End If
If Not oCell.Borders(wdBorderBottom).Color = RGB(0, 128, 0) Then
oCell.Borders(wdBorderBottom).Color = RGB(0, 128, 0)
End If
Next oCell
Next oTbl
lbl_Exit:
Exit Sub
End Sub