How would this be useful?

regardless try this.

Sub ColorCompanyDuplicates()
'Updateby Extendoffice 20160704
' with changes for excelforum 20170721
    Dim xRg As Range
    Dim xTxt As String
    Dim xCell As Range
    Dim xChar As String
    Dim xCellPre As Range
    Dim xCIndex As Long
    Dim xCol As Collection
    Dim I As Long
    On Error Resume Next
    If ActiveWindow.RangeSelection.Count > 1 Then
      xTxt = ActiveWindow.RangeSelection.AddressLocal
    Else
      xTxt = ActiveSheet.UsedRange.AddressLocal
    End If
    Set xRg = Range("F2:F1289")
    If xRg Is Nothing Then Exit Sub
    xCIndex = 2
    Set xCol = New Collection
    For Each xCell In xRg
      On Error Resume Next
      xCol.Add xCell, xCell.Text
      If Err.Number = 457 Then
      xCIndex = xCIndex + 1
        xCell.EntireRow.Interior.ColorIndex = xCIndex
        Else
        xCIndex = 2
      End If
      On Error GoTo 0
    Next
End Sub