error with connect datagrid view column to data base

i want to connect a column of data gridview with type combo box to a data base and with change value of this the data source of second column with type combo box change my code is correct and work but with change first column and see data in secondd column see this error how can i solve this???
 
the following exception occured in the datagridview
system.argumentexception:datagridviewcomboboxcell value is not valid
to replace this default dialog please handle the data error event
 
please help me.........

private void foroosh_Load(object sender, EventArgs e)
        {
            DataTable p = new System.Data.DataTable();
            p = selectcolor("type","");
         (dataGridView2.Columns[0] as DataGridViewComboBoxColumn).DataSource = p;
         (dataGridView2.Columns[0] as DataGridViewComboBoxColumn).DisplayMember = "type";
         DataTable pc = new System.Data.DataTable();
            pc = sel();
         (dataGridView2.Columns[4] as DataGridViewComboBoxColumn).DataSource = pc;
         (dataGridView2.Columns[4] as DataGridViewComboBoxColumn).DisplayMember = "color";
}
 

 

 private void dataGridView2_CellEnter(object sender, DataGridViewCellEventArgs e)
        {
 
            DataTable pe = new System.Data.DataTable();
            string pi;
            int f;
            if (e.ColumnIndex == 2)
            {
                pe = selectcolor("tip", "where type= '" + dataGridView2.Rows[0].Cells[0].Value.ToString() + "'");
                (dataGridView2.Columns[2] as DataGridViewComboBoxColumn).DataSource = pe;
                (dataGridView2.Columns[2] as DataGridViewComboBoxColumn).DisplayMember = "tip";
            }
            else if(e.ColumnIndex == 1)
            {
                pi = varab(dataGridView2.Rows[e.RowIndex].Cells[0].Value.ToString());
                if (pi == "ميلادي")
                {
                    for (f = 1950; f <= 2020; f++)
                        (dataGridView2.Columns[1] as DataGridViewComboBoxColumn).Items.Add(f);
                }
                else
                {
                    for (f = 1300; f <= 1400; f++)
                        (dataGridView2.Columns[1] as DataGridViewComboBoxColumn).Items.Add(f);
                }
            }
 

            }