/**
         * generates random colors for the ProgressBar
         */
        protected void SwitchColor()
        {
            Random r           = new Random();
            int    randomColor = Color.Rgb(r.Next(256), r.Next(256), r.Next(256));

            holoCircularProgressBar.SetProgressColor(randomColor);

            randomColor = Color.Rgb(r.Next(256), r.Next(256), r.Next(256));
            holoCircularProgressBar.SetProgressBackgroundColor(randomColor);
        }