//RichTextBox ZMIANY KOLORU LINII;

        public void ChangeLineForeColor(Color color, string expression, int numerLinii)
        {
            int start  = KOD_RichTextBox.GetFirstCharIndexFromLine(numerLinii);
            int koniec = expression.Length;

            KOD_RichTextBox.SelectionStart  = start;
            KOD_RichTextBox.SelectionLength = koniec;
            KOD_RichTextBox.SelectionColor  = color;
        }
 public void ResetLinesColor()
 {
     KOD_RichTextBox.SelectAll();
     KOD_RichTextBox.SelectionColor = Color.Black;
 }