SheetJS xlsx-cell styling
Styling is only available in Pro Version of SheetJS. But I think you are using community version(free version). In Community version styling is not available.
You can check here official information:
We also offer a pro version with performance enhancements, additional features like styling, and dedicated support.
I used sheetjs-style (which is a fork of sheetjs) to add formatting to cells in excel file.
ws["A1"].s = // set the style for target cell font: { name: '宋体', sz: 24, bold: true, color: { rgb: "FFAA00" } },};It's very easy. However, you have to add style to each individual cell. It's not convenient to add style to a range of cells.
UPDATE: The official example use color "FFFFAA00". But I removed the first "FF" and it still works as before. The removed part is used for transparency (see COLOR_SPEC in Cell Styles), but somehow it has no effect when I change it or remove it.