Select a group of spreadsheets and form with them a kind of chapter, with the same color as the guide. So when you click on a chapter all spreadsheets are available for viewing (as is current Excel) and those that don't belong are collapsed (hidden) within your chapter. In the attached file only the yellow tabs would appear and below them the chapter names. When you clicked on the Green chapter the green tabs would be displayed and the others hidden. It's a way of working with multiple linked documents within Excel with a clearer view of spreadsheets that really matter at that time.
The idea is good, it is worth reading. It will greatly facilitate the organization of documents in Excel.