GrapeCity.Win.Spread.InputMan.CellType.GcComboBoxCellType gccombo = new GrapeCity.Win.Spread.InputMan.CellType.GcComboBoxCellType();
gccombo.Items.AddRange(new string[] { "Feta", "Havarti", "Swiss" });
gccombo.Items[0].BackColor = Color.Beige;
gccombo.Items[1].BackColor = Color.Cornsilk;
gccombo.Items[2].BackColor = Color.PeachPuff;
gccombo.ListHeaderPane.BackColor = Color.Blue;
gccombo.ListHeaderPane.Font = new Font("Calibri", 10);
gccombo.ListHeaderPane.Visible = true;
gccombo.ListHeaderPane.AutoHeight = false;
gccombo.ListHeaderPane.Height = 30;
fpSpread1.Sheets[0].Cells[1, 1].CellType = gccombo;
fpSpread1.Sheets[0].Columns[1].Width = 200;
fpSpread1.Sheets[0].Rows[1].Height = 40;