Here is custom.css. I don’t really understand what the .CX2 is but I saw it on several related posts so I tried it. I also tried without it, but no luck either way. It seems like it’s just not applying anything in this file so I’m hoping it’s just something basic that I’m missing.

custom.css

 body {
	.CX2 .event .personal {
  	color:#ffffff;
  	background-color:#000000;
} 	
	.CX2 .event .personal .fullday {
  	color:#000000;
	background-color:#FFA500;
}
      }

Config.js

var config = {
	address: "localhost", // Address to listen on, can be:
	                      // - "localhost", "127.0.0.1", "::1" to listen on loopback interface
	                      // - another specific IPv4/6 to listen on a specific interface
	                      // - "", "0.0.0.0", "::" to listen on any interface
	                      // Default, when address config is left out, is "localhost"
	port: 8080,
	ipWhitelist: [], // Set [] to allow all IP addresses
	                                                       // or add a specific IPv4 of 192.168.1.5 :
	                                                       // ["127.0.0.1", "::ffff:127.0.0.1", "::1", "::ffff:192.168.1.5"],
	                                                       // or IPv4 range of 192.168.3.0 --> 192.168.3.15 use CIDR format :
	                                                       // ["127.0.0.1", "::ffff:127.0.0.1", "::1", "::ffff:192.168.3.0/28"],

	language: "en",
	timeFormat: 12,
	units: "imperial",

	modules: [
		{
  module: 'MMM-CalendarExt2',
  config: {
    calendars : [
      {
	name: "Personal",
	url: "https://calendar.google.com/calendar/ical/***********************/basic.ics",
	icon: "noto-ice-hockey",
	className: "personal",
	scanInterval: 5*60*1000,
      },
      {
	name: "Ducks Schedule",
        url: "http://ducks.ice.nhl.com/schedule/full.ics",
      },
      {
	name: "Sharks Schedule",
	url: "http://sharks.ice.nhl.com/schedule/full.ics",
	classname: "sharks",
      },
    ],
    views: [
      {
        mode: "daily",
      },
      {
   	mode: "month",
    	position: "fullscreen_below",
    	calendars: [],
  },
    ],
    scenes: [
      {
        name: "DEFAULT",
      },
    ],
  },
},
	
	]

};

/*************** DO NOT EDIT THE LINE BELOW ***************/
if (typeof module !== "undefined") {module.exports = config;}