modify suggestive behaviour of datagridview

Question

I have a textbox in my form and when the user types inside it , a datagridview (named dataGridView1) which was hidden earlier becomes visible and used to display similar results by using dataview. below is the code

   private void Form2_Load(object sender, EventArgs e)
        {            
            dataGridView1.Visible = false;
            dataGridView1.ColumnHeadersVisible = false;            
            using (SqlConnection conn = new SqlConnection())
            {
                conn.ConnectionString = "Data Source =DESKTOP-197P3FU\\SQLEXPRESS;Integrated security=SSPI;database=unk";
                // Create a data adapter to retrieve data from the table
                SqlDataAdapter adapter = new SqlDataAdapter($"SELECT * FROM ledgernames", conn);
                // Initialize the dataset
                dataSet = new DataSet();
                // Fill the dataset with the table data
                adapter.Fill(dataSet);
            }
            dataGridView1.DataSource = dataSet.Tables[0];
      

        }
 private void customtextbox3_Enter(object sender, EventArgs e)
        {
            dataGridView1.Visible = true;

            // Hide unwanted columns
            dataGridView1.Columns["id"].Visible = false;
            dataGridView1.Columns["current_balance"].Visible = false;
            dataGridView1.Columns["opening_balance"].Visible = false;
            // 
            dataGridView1.CurrentCell = dataGridView1.Rows[0].Cells[1];
        }

 private void customtextbox3_TextChanged(object sender, EventArgs e)
        {
            string searchText = customtextbox3.Text.Trim();
             dataView = dataSet.Tables[0].DefaultView;

            if (searchText.Length > 0) // 
            {
                dataView.RowFilter = $"name LIKE '%{searchText}%'";
                if (dataView.Count == 0) // check if no rows match the filter
                {
                    searchText = searchText.Substring(0, searchText.Length - 1);
                    customtextbox3.Text = searchText;
                }
                else
                {

                    dataGridView1.DataSource = dataView;
                }
            }
            else
            {

                dataGridView1.DataSource = dataSet.Tables[0];
            }
            customtextbox3.Select(customtextbox3.Text.Length, 0); // Set cursor at the end
        }

  private void customtextbox3_KeyDown(object sender, KeyEventArgs e)
        {
           
            if (dataGridView1.CurrentCell == null)
            {
                return;
            }
            else
            {
                 rpos = dataGridView1.CurrentCell.RowIndex;
                 cpos = dataGridView1.CurrentCell.ColumnIndex;

                switch (e.KeyCode)
                {
                 case Keys.Up:

                        rpos--;
                        if (rpos >= 0) dataGridView1.CurrentCell = dataGridView1.Rows[rpos].Cells[cpos];
                        e.Handled = true;
                        break;
                 case Keys.Down:
                       
                        rpos++;
                        if (rpos < dataGridView1.Rows.Count) dataGridView1.CurrentCell = dataGridView1.Rows[rpos].Cells[cpos];
                        e.Handled = true;
                        break;
                 case Keys.Enter:
                        {
                            if (dataGridView1.Rows.Count > 0)
                            {
                                dataGridView1.Visible = false;
                                customtextbox3.Text = dataGridView1.SelectedRows[0].Cells[1].Value.ToString();
                                customControl11.Focus();
                               
                                dataView.RowFilter = ""; // resets the filter to its starting state 
                            }
                            e.Handled = e.SuppressKeyPress = true;
                            break;
                        }
                }
            }
        }
       

what i am trying to get is when a perfect similar word like if user types ris in textbox , the suggestions were (by datagridview1) would be prisha , enterprises , rishabh , rishi . but the last two should be in bold and blue color (as they start with ris ) and when the user by using

customtextbox3_KeyDown

event tries to move up and down , the very first time the movement of up and down should start from rishabh . I have tried many options but none of them work . Please suggest the code for that .