Hello @AndreaC,
The toExcel method allows exporting only styles that were actually applied. Unfortunately, a view-less instance of a DataCollection can’t handle them. As an option, it is possible to dynamically create a datatable with needed config, export it and destroy afterwards.
Please check the snippet: https://snippet.webix.com/rxfjf5kg
An alternative would be to add cell styles directly to the collection options.
For export to Excel we are using SheetJS library . How to add styles described here
Please check the snippet: https://snippet.webix.com/tjr3xqq9