Select all/none for viewing multiple colours/calendars

Hi

I use several different colours/calendars within a single Google calendar account which I use with OneCalendar.

When trying to see just one colour (which represents, for example, holidays), I have to unselect around 10-15 colours just see the one I'm interested in.

If it were possible to click once on a 'select all' or 'select none' option then this would speed up selection significantly.

Also, some colours represent individual Google calendars, so having those sorted at the top of the list would also help.

This is for iOS and Windows 11