private static void drawUncoloredPattern(PdfDocument pdf)
{
PdfTilingPattern pattern = pdf.AddUncoloredPattern(5, 5, new PdfRgbColorSpace());
fill(pattern);
PdfCanvas canvas = pdf.GetPage(0).Canvas;
canvas.Brush.Pattern = pattern;
canvas.Brush.Color = new PdfRgbColor(0, 255, 0);
canvas.DrawString(new PointF(50, 150), "Uncolored Pattern colored green");
}