Hi,
I am sorry that you have problems! Please watch this video:
It was created using the latest version of CalenGoo. As you can see in my test, the color of the event changed when changing the calendar.
Did you maybe set an individual color for your event? CalenGoo has several methods to assign colors to events:
Individual colors are preserved when moving an event to a different calendar. Please check if your events have an individual color set.
Please don't hesitate to contact me again if you have further questions!
Kind regards
Dominique Gunia