vb.net DataGridViewにボタンの追加と色をつける

初期設定でPopup指定
        Dim butcol As New DataGridViewButtonColumn
        butcol.FlatStyle = FlatStyle.Popup
        butcol.UseColumnTextForButtonValue = False
        butcol.Text = "選択"
        butcol.Name = "SELECTS"
        GridSS.Columns.Add(butcol)


ボタンの色のセット

                GridSS(8, i).Style.BackColor = Color.Blue
                GridSS(8, i).Style.ForeColor = Color.Yellow
                GridSS(8, i).Value = "選択"

イベントは
   Private Sub DataGridView1_CellContentClick(ByVal sender As Object, ByVal e As DataGridViewCellEventArgs) _
        Handles GridSS.CellContentClick
        Dim dgv As DataGridView = CType(sender, DataGridView)
        '"Button"列ならば、ボタンがクリックされた
        Dim i, k As Short
        Select Case dgv.Columns(e.ColumnIndex).Name
            Case "SELECTS"

    End Sub