colour code datagridview

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }
    DataGridView DataGridView1 = new DataGridView();
    Button ButtonUpdate = new Button();
    BindingSource BindingSource1 = new BindingSource();
    DataTable DataTable1 = new DataTable();
    Color[] colorTable;
    private void Form1_Load(object sender, EventArgs e)
    {
        colorTable = new Color[]{
               Color.Blue, Color.Red, Color.Green,
               Color.Pink, Color.Plum, Color.Cyan};
        DataTable1.Columns.Add("ItemId", typeof(int), null);
        {
            DataTable1.Rows.Add(1);
            DataTable1.Rows.Add(2);
            DataTable1.Rows.Add(2);
            DataTable1.Rows.Add(5);
            DataTable1.Rows.Add(5);
            DataTable1.Rows.Add(6);
            DataTable1.Rows.Add(6);
            DataTable1.Rows.Add(7);
            DataTable1.Rows.Add(7);
        }
        BindingSource1.DataSource = DataTable1;
        DataGridView1.DataSource = BindingSource1;

        DataGridView1.Dock = DockStyle.Fill;
        this.Controls.Add(DataGridView1);
        DataGridView1.CellFormatting += new DataGridViewCellFormattingEventHandler(DataGridView1_CellFormatting);

    }

    void DataGridView1_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
    {
        if (e.ColumnIndex == 0)
        {
            try
            {
                int val = (int)DataGridView1.Rows[e.RowIndex].Cells[e.ColumnIndex].Value;
                e.CellStyle.BackColor = colorTable[val % 6];
            }
            catch
            {
                return;
            }
        }
    }
}