BorderLineColor

public Color BorderLineColor { get; set; }

[C#]
//实例化一个工作簿对象
Workbook workbook = new Workbook();
Worksheet worksheet = workbook.Worksheets[0];
//在工作表中行列索引均为1的单元格位置添加图片。它是“B2”单元格
int imgIndex = worksheet.Pictures.Add(1, 1, "example.jpeg");
//获取插入的图片对象
Picture pic = worksheet.Pictures[imgIndex];
//设置图片的边框颜色
pic.BorderLineColor = Color.Red;
//保存excel文件。
workbook.Save("result.xlsx");