datagrid view cell click

Try this :

 if (dataGridView1[e.ColumnIndex, e.RowIndex].Style.BackColor == Color.Empty)
    if e.ColumnIndex<>10 then
               dataGridView1[e.ColumnIndex, e.RowIndex].Style.BackColor = Color.Black;// 0x7D0000255;
    end if
else
    if e.ColumnIndex<>10 then
                dataGridView1[e.ColumnIndex, e.RowIndex].Style.BackColor = Color.Empty;
    end if