Different types of booking possible?

Hi, this plugin is almost perfect to use on a client website. The only thing is that I need two kind of bookings (‘booked’ and ‘unavailable for groups’), so basically just two different colors on the calendar.

I know this plugin is free, but is there any possibility of achieving this, or pointing me in the right direction for modifying the plugin to my needs?

https://www.ads-software.com/plugins/8-degree-availability-calendar/