StringTwoColor stc = new StringTwoColor(jl1, Color.RED, Color.gray, 0.8);//0.8为比值

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
 
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
 
public class StringTwoColor{
 
 private BufferedImage buffImg;
 
 /**
 * @param label 显示字体的JLabel
 * @param c1 颜色1
 * @param c2 颜色2
 * @param ratio 颜色1与颜色2所占部分的比值
 */
 public StringTwoColor(JLabel label, Color c1, Color c2, double ratio){
 
 //获取字符串的宽（显示在屏幕上所占的像素px）
    FontMetrics metrics = label.getFontMetrics(label.getFont());
    int width = metrics.stringWidth(label.getText());
    int height = metrics.getHeight();
    height+=label.getFont().getSize();
  
    //构造一个具有指定尺寸及类型为预定义图像类型之一的 BufferedImage
 buffImg = new BufferedImage(width,height,BufferedImage.TYPE_4BYTE_ABGR);
 BufferedImage buffImg1 = new BufferedImage(width,height,BufferedImage.TYPE_4BYTE_ABGR);
 BufferedImage buffImg2 = new BufferedImage(width,height,BufferedImage.TYPE_4BYTE_ABGR);
 
 //通过BufferedImage创建一个 Graphics2D对象
 Graphics2D g1 = buffImg1.createGraphics();
 Graphics2D g2 = buffImg2.createGraphics();
 
 //设置抗锯齿
 g1.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
 g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
 
 //设置字体
 g1.setFont(label.getFont());
 g2.setFont(label.getFont());
 
 //设置颜色
 g1.setColor(c1);
 g2.setColor(c2);
 
 //画字符串
 g1.drawString(label.getText(), 0, height-label.getFont().getSize());
 g2.drawString(label.getText(), 0, height-label.getFont().getSize());
 
 //按照比例清除相关的像素点
 if(ratio<1 && ratio>0){
 
 int rgb = 0x00000000;
 
 //清除buffImg1
 for(int y=0;y=width*ratio;x--){
  buffImg1.setRGB(x, y, rgb);
 }
 }
 
 //清除buffImg2
 for(int y=0;y=width*ratio;x--){
  buffImg.setRGB(x,y,buffImg2.getRGB(x, y));
 }
 }
 }
 }
 
 /**
 * 获取处理完的ImageIcon
 * @return
 */
 public ImageIcon getImageIcon(){
 
 Image img = buffImg;
 ImageIcon imgIcon = new ImageIcon(img);
 
 return imgIcon;
 }
 
 public static void main(String[] args) {
 
 JFrame jf = new JFrame();
 jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 jf.setSize(300, 200);
 jf.setLocationRelativeTo(null);
 jf.setLayout(new BorderLayout());
 
 JLabel jl1 = new JLabel("梦");
 //JLabel jl1 = new JLabel("梦里梦到醒不来的梦");
 jl1.setFont(new Font("幼圆",Font.PLAIN,30));
 StringTwoColor stc = new StringTwoColor(jl1, Color.RED, Color.gray, 0.7);
 
 //获取处理完的图片并显示
 JLabel jl2 = new JLabel(stc.getImageIcon());
 jf.add(jl2, BorderLayout.CENTER);
 
 jf.setVisible(true);
 }
 
}