Venue Background Color for Events on Calendar

I’m brand new to WordPress as our tech position is currently vacant so they needed someone to keep the website/calendar updated. I work at a library and under Events–> Venues I have the list of all of the library branches set up as separate venues. When I create a new event to add to the calendar (we have a separate Children and Adults calendar) I’m able to choose from which venue that it will be held at, but I’m hoping I can assign a different color to each of the venues so that on the main calendar the events are color coded by venue. I’m very new to HTML and am not even sure where to start to try to do this. Any help is appreciated!

Adult calendar: https://www.stanlycountylibrary.org/
Children’s calendar: https://www.stanlycountylibrary.org/children/