NPOI border styles appear differently in macOS / iOS Preview

Question

The following style

var style1 = (XSSFCellStyle)workbook.CreateCellStyle();
var pink = new XSSFColor(new byte[] { 228, 52, 145 });
style1.SetBorderColor(BorderSide.TOP, pink);
style1.BorderTop = BorderStyle.Medium;

Renders correctly in Excel

But not in macOS / iOS Preview

How could I make the borders appear correctly?

Answer 1

Finally, applying borders everywhere fixed the issue in macOS / iOS Preview. I added:

var grayColor = new XSSFColor(new byte[] { 210, 210, 223 });
style1.SetBorderColor(BorderSide.RIGHT, grayColor);
style1.BorderRight = BorderStyle.Thin;
style1.SetBorderColor(BorderSide.LEFT, grayColor);
style1.BorderLeft = BorderStyle.Thin;
style1.SetBorderColor(BorderSide.BOTTOM, grayColor);
style1.BorderBottom = BorderStyle.Thin;