Identify different CalDav calendars

Hi Im trying to find a way to use two calendars using CalDAV personal, which I have configured successfully, but then be able to somehow put both sets of items (Active, eventnr1, eventnr2 etc) together, sort by date and time order, but also be able to identify which items are from which calendar.

I ultimately want to display a single widget in HABPanel that shows the next 4 calendar events in chronological , irrespective of which calendar they come from, but have them color coded so from calendar 1 they are one colour and calendar 2 a different colour.

Anyone have any ideas on how this could be achieved?