Custom Color Set Lost after adding appointments_style to functions.php

I've been playing around with the Appointments+ plugin, which has been a lot of fun. A question: I've added add_theme_support( "appointments_style" ) to functions.php so that I can customize the css to my own specifications (ie. front.css is not called), however this has caused the calendar of availability to lose all the colors chosen from the custom color set (the calendar does not have any colors at all now). Any idea how I can get these colors back?

Thanks!