Mareo Code

We can use for this _CellFormatting event. See below example:

private void DataGridView1_CellFormatting(object sender,
                        DataGridViewCellFormattingEventArgs e)
{
    DataGridView gv = (DataGridView)sender;

    if (gv.Columns[e.ColumnIndex].Name == "ColumnName")
    {
        // If cell has a value and contains char '-'
        if (e.Value != null && e.Value.ToString().Contains("-"))
        { // Change cell text color to red
            e.CellStyle.ForeColor = Color.Red;
            //e.CellStyle.Font = new Font("Arial", 10, FontStyle.Bold);
        }
    }
}