Welcome to the forum, bernieb.
I'm not using Google Calendar, but I know there were some problems with the holidays calendars in the last month. Supposedly, this has been started to be fixed by Google.
(
www.rainlendar.net/cms/index.php?option=com_kunena&Itemid=42&func=view&catid=3&id=11491&limit=6&limitstart=12#17280). Maybe someone else could give you a better answer.
The color events are in fact categories. The best way to achieve this using Google Calendar is to create several calendars, one by each category, and then assign a visual category (under Options... -> Calendar -> Option. For local calendars, you can assign the category for each individual event/task without the need to be in the same calendar)