Syncing CalenGoo directly with Mozilla Lightning/Sunbird
CalenGoo can be synced with Google Calendar and the Android calendar. Via the Android calendar it is possible to sync CalenGoo directly with Mozilla Thunderbird Lightning and Mozilla Sunbird without syncing via the Internet.
You can use the program BirdieSync for this purpose. It consist of a PC program, which integrates into Lightning/Sunbird and syncs to an Android app. You can also sync multiple calendars this way.
If all calendars have the same color in CalenGoo after syncing, you can simply change that color by tapping on a calendar’s name in CalenGoo under "Settings", "Visibility/Download".
And you can certainly display calendars from different sources side by side in CalenGoo. This way you can e.g. display holidays and shared calendars from Google Calendar together with local calendars or Lightning/Sunbird calendars.