Color Code Calendar?

I’m still a bit of a newbie here, but have scoured and read so much of the community forums… I’m thinking that @Jeff_Hager is the main calendar guru - so here goes my request and question… I am developing a calendar made a lot like another user (she called it pickcalendar) - and I want to know if it’s possible to 1. color code the calendar - as it’s purpose it to track something… and also - can I then have it show 2 people tracking in different colors - and have them BOTH show up on overlapping days?
Does that make any sense? I suppose I could do it with tiny icons or colored “dots”, but it it possible to do and do you have any suggestions how I would make this work? Thanks in advance to anyone who cares to respond!

Do you have a link or some images so we can have a visualized version of what you’re trying to achieve?