PDFOne Java可以在创建PDF时或者是对存在的PDF文件进行字体以及颜色的设置，开发人员可以轻松使用 PdfFont对象来实现该功能，具体可以参考下面的部分代码：

// Create a PdfDocument instance
PdfDocument doc = new PdfDocument();
try {
  // Load an existing PDF document
  doc.load("sample_doc1.pdf");
  // Create font objects
  PdfFont fontArialItalic =
    PdfFont.create("Arial", // name of installed font
                   PdfFont.ITALIC | PdfFont.STROKE_AND_FILL,
                   18,
                   PdfEncodings.WINANSI); 
  PdfFont fontTahomaNormal =
    PdfFont.create("tahoma.ttf", // pathname of a font file
                   PdfFont.STROKE_AND_FILL,
                   48,
                   PdfEncodings.WINANSI);

  // Write text on page 1 using the Arial font
  doc.writeText("Hello again, World!",
                fontArialItalic, // font
                100, 50);

  // Change font properties
  fontTahomaNormal.setStrokeWidth(2);
  fontTahomaNormal.setStrokeColor(Color.RED);
  fontTahomaNormal.setColor(Color.ORANGE);
  
  // Write more text on page 1 using the Tahoma font
  doc.writeText("Hello again, World!",
                fontTahomaNormal, // font
                100, 100);
  
  // Write modified document to output file
  doc.save("sample_doc3.pdf");
  doc.close();
} catch (IOException | PdfException e) {
  // TODO Auto-generated catch block
  e.printStackTrace();
}