DataGridViewComboxColumn Background changed to color Black !

This is what I've done >>

//setting the datagrid
private void SetDataGridServer()
{
dataGrdServer.AutoGenerateColumns = false;
dataGrdServer.VirtualMode = true;
dataGrdServer.DataSource = _svrs;

AddDataGridServerColumns();

dataGrdServer.RowHeadersVisible = false;
dataGrdServer.AutoSizeColumnsMode = DataGridViewAutoSizeColumnsMode.Fill;
dataGrdServer.SelectionMode = DataGridViewSelectionMode.FullRowSelect;

DataGridViewCellStyle style = new DataGridViewCellStyle();
style.BackColor = Color.Cornsilk;
style.ForeColor = Color.Brown;

dataGrdServer.AlternatingRowsDefaultCellStyle = style;
dataGrdServer.Columns[1].CellTemplate.Style = dataGrdServer.DefaultCellStyle;
dataGrdServer.BackgroundColor = Color.Beige;
}

//Add the combox Column
private void AddComboxColumn()
{
DataGridViewComboBoxColumn cboColum = new DataGridViewComboBoxColumn();
{
cboColum.DataSource = Enum.GetValues(typeof(EApplicationState));
cboColum.DataPropertyName = "State";
cboColum.HeaderText = "State";
cboColum.MaxDropDownItems = 4;
cboColum.FlatStyle = FlatStyle.Flat;
cboColum.DisplayStyle = DataGridViewComboBoxDisplayStyle.DropDownButton;
}
dataGrdServer.Columns.Insert(1, cboColum);
}

private void dataGrdServer_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{
Utils.Debug("EditingContorls",e.Control.ToString());

DataGridViewComboBoxEditingControl combo = (DataGridViewComboBoxEditingControl) e.Control;
combo.SelectedIndexChanged += new EventHandler(combo_SelectedIndexChanged);
combo.TextChanged += new EventHandler(combo_TextChanged);
}

void combo_TextChanged(object sender, EventArgs e)
{
Utils.Debug("Something Changed In TextChanged");
Utils.Debug(dataGrdServer.SelectedCells[1].Value);
}
void combo_SelectedIndexChanged(object sender, EventArgs e)
{
Utils.Debug(((DataGridViewComboBoxEditingControl) sender).SelectedValue.ToString());
}