The little black marker in the lower right corner of cell H whatever row that is indicates column I is
not part of the table.
Try this
Code:
Sub CloudForgiven()
Dim colIndex As Variant
Dim StrtRow As Long, EndRow As Long, i As Long
Dim oLo As ListObject
colIndex = Application.InputBox("Enter a column that you want to add: ", "What column?")
If colIndex = "" Then Exit Sub
With ThisWorkbook.Sheets("Sheet1")
.Columns(colIndex).Insert shift:=xlRight '<--| reference column you want to insert
'sheet row numbers from table rows
Set oLo = .ListObjects(1) '<~~ first table on sheet
With oLo
StrtRow = .ListRows(1).Range.Row
EndRow = .ListRows.Count + StrtRow - 1
End With
For i = StrtRow To EndRow
.Cells(i, colIndex).Interior.Color = .Cells(i, 1).DisplayFormat.Interior.Color
Next i
End With
End Sub