//Loop through all rows. for (int x = 0; x < yourGridName.Rows.Count; x++) { //Change cell colour to Red. if (endDate < DateTime.Now) { //Loop through all cells in that row and change its color. for (int y = 0; y < yourGridName.Rows[x].Cells.Count; y++) { yourGridName.Rows[x].Cells[y].Style.BackColor = System.Drawing.Color.Red; } } }