You should have the color-changing code in a method like this:
namespace TE
{
public class High
{
public static void ChangeMyColor(RichTextBox rtb)
{
rtb.SelectionColor = Color.Black;
rtb.SelectionFont = new Font("Courier New", 10, FontStyle.Regular);
}
}
}
Call it like this:
private void TextChangedEvent(object sender, EventArgs e)
{
TE.High.ChangeMyColor(rtb);
}