.richTextBox1.SelectionColor = Color.Black; Font font = new Font(FontFamily.GenericMonospace,10,FontStyle.Regular); this.richTextBox1.SelectionFont = font...
int pos=richTextBox1.Find(str);richTextBox1.SelectionStart=pos;richTextBox1.SelectionLength=str.Length; richTextBox1.SelectionFont=f;richTextBox1.SelectionColor...