1. 颜色概述

颜色Color是单元格的基本样式，单元格默认颜色为黑色

- 单元格边框颜色  - 单元格填充色  - 单元格字体颜色

2. 预定自颜色

POI中预定义了56种颜色，索引从0x8 - 0x40， 索引0x40定义一种默认颜色 - 黑色

org.apache.poi.ss.usermodel.IndexedColors
org.apache.poi.hssf.util.HSSFColor$HSSFColorPredefined

// 设置填充色
cellStyle.setFillForegroundColor(IndexedColors.BLUE.getIndex());
cellStyle.setFillForegroundColor(HSSFColorPredefined.BLUE.getIndex());

// 设置字体颜色
font.setColor(IndexedColors.WHITE.getIndex());
font.setColor(IndexedColors.WHITE.getIndex());

3. 自定义颜色

当56预定义颜色无法满足需要时，可以自定义颜色，HSSFColor和XSSFColor自定义颜色方式完全不同

3.1 自定义HSSFColor

1. 根据HSSFWorkbook获取自定义调色面板HSSFPalette 
  2. 用自定义颜色覆盖索引[0x8, 0x40)
  3. 使用覆盖的索引，即自定义的颜色

// 获取工作簿的调色面板
HSSFPalette palette = hssfWorkbook.getCustomPalette();
// 将调色面板中蓝色索引替换为红色
palette.setColorAtIndex(HSSFColorPredefined.BLUE.getIndex(), (byte) 255, (byte) 0, (byte) 0);
// 会出现红色字体
font.setColor(HSSFColorPredefined.BLUE.getIndex());

3.2 自定义XSSFColor

1. 根据一个java.awt.Color实例或RGB字节数组创建一个XSSFColor实例color
  2. 直接传递实例color对象

XSSFColor color = new XSSFColor(new java.awt.Color(255, 0, 0));
xSSFCellStyle.setFillForegroundColor(color);
xSSFFont.setColor(color);

4. HSSFColor实例

1. 默认蓝色背景，白色字体
2. 自定义后红色背景，黑色字体

package hssf.sheet.color;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

import org.apache.poi.hssf.usermodel.HSSFPalette;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.hssf.util.HSSFColor.HSSFColorPredefined;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.FillPatternType;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.IndexedColors;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;

/** * 使用默认调色面板 * */
public class ExportHSSFColor {
    public static void main(String[] args) throws Exception {
        File file = new File("C:\\Users\\Administrator\\Desktop\\test.xls");
        if (file.exists()) {
            file.delete();
        }
        BufferedOutputStream out = null;
        try {
            out = new BufferedOutputStream(new FileOutputStream("C:\\Users\\Administrator\\Desktop\\test.xls"));
            exportExcel(out);
        } finally {
            out.close();
        }
    }

    /** * @param out * @throws IOException */
    private static void exportExcel(BufferedOutputStream out) throws IOException {
        HSSFWorkbook workbook = new HSSFWorkbook();
        Sheet sheet = workbook.createSheet();
        sheet.setColumnWidth(0, 20*256);
        Row row = sheet.createRow((short) 0);
        Cell cell = row.createCell((short) 0);
        cell.setCellValue("调色板");

        /*****************************自定义颜色**************************************************/
        // 获取工作簿的调色面板
        HSSFPalette palette = workbook.getCustomPalette();
        // 将调色面板中蓝色索引替换为红色
        palette.setColorAtIndex(HSSFColorPredefined.BLUE.getIndex(), (byte) 255, (byte) 0, (byte) 0);
        // 将白色索引替换为黑色
        palette.setColorAtIndex(HSSFColorPredefined.WHITE.getIndex(), (byte) 0, (byte) 0, (byte) 0);
        /**************************************************************************************/

        CellStyle style = workbook.createCellStyle();
        // 填充色
        style.setFillForegroundColor(HSSFColorPredefined.BLUE.getIndex());
//      style.setFillForegroundColor(IndexedColors.BLUE.getIndex());
        style.setFillPattern(FillPatternType.SOLID_FOREGROUND);

        // 字体颜色
        Font font = workbook.createFont();
        font.setColor(HSSFColorPredefined.WHITE.getIndex());
        style.setFont(font);

        cell.setCellStyle(style);
        workbook.write(out);
    }
}

5. XSSFColor实例

package hssf.sheet.color;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

import org.apache.poi.hssf.util.HSSFColor.HSSFColorPredefined;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.CellStyle;
import org.apache.poi.ss.usermodel.FillPatternType;
import org.apache.poi.ss.usermodel.Font;
import org.apache.poi.ss.usermodel.IndexedColors;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.xssf.usermodel.XSSFCellStyle;
import org.apache.poi.xssf.usermodel.XSSFColor;
import org.apache.poi.xssf.usermodel.XSSFFont;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class ExportXSSFColor {

    public static void main(String[] args) throws Exception {
        File file = new File("C:\\Users\\Administrator\\Desktop\\test.xlsx");
        if (file.exists()) {
            file.delete();
        }
        BufferedOutputStream out = null;
        try {
            FileOutputStream fileOutputStream = new FileOutputStream("C:\\Users\\Administrator\\Desktop\\test.xlsx");
            out = new BufferedOutputStream(fileOutputStream);
            exportExcel(out);
        } finally {
            out.close();
        }
    }

    /** * @param out * @throws IOException */
    private static void exportExcel(BufferedOutputStream out) throws IOException {
        XSSFWorkbook workbook = new XSSFWorkbook();
        Sheet sheet = workbook.createSheet();
        sheet.setColumnWidth(0, 20*256);
        Row row = sheet.createRow((short) 0);
        Cell cell = row.createCell((short) 0);
        cell.setCellValue("调色板");

        // 创建一个单元格样式
        XSSFCellStyle style = workbook.createCellStyle();
        cell.setCellStyle(style);

        /*****************************使用默认颜色**************************************************/
        // 填充色
//      style.setFillForegroundColor(IndexedColors.BLUE.getIndex());
        style.setFillForegroundColor(HSSFColorPredefined.BLUE.getIndex());
        style.setFillPattern(FillPatternType.SOLID_FOREGROUND);

        // 字体颜色
        Font font = workbook.createFont();
        font.setColor(IndexedColors.WHITE.getIndex());
        style.setFont(font);
        /**************************************************************************************/

        /*****************************自定义颜色**************************************************/
        XSSFColor color = new XSSFColor(new java.awt.Color(255, 0, 0));
        style.setFillForegroundColor(color);
        style.setFillPattern(FillPatternType.SOLID_FOREGROUND);

        XSSFColor color1 = new XSSFColor(new java.awt.Color(0, 0, 0));
        // 字体颜色
        XSSFFont font1 = workbook.createFont();
        font1.setColor(color1);
        style.setFont(font1);
        /**************************************************************************************/

        workbook.write(out);
    }
}