How to create a custom calendar app with categories for events in android?

First of all, I apologize for asking "What have you done" ?, because I have no idea where to start. Now about the problem

I need to develop my own calendar application that allows the user to add events to the calendar under different categories with different colors for each category. I have not been able to find any piece of code that supports categories for events (I know that the android calendar contract provider does not provide categories for events). Then only the option creates multiple calendars for different categories. I read some where we can develop the app as a calendar using the sync adapter but couldn't find a good tutorial :(.

• I like to know how to design a calendar using a sync adapter.

• Is it possible to create multiple calendars from within the app (if yes, how)

• Can I provide a function to create calenders by a user

I am confused if this is possible, I am very happy with everything, as it provides any link or suggestions even one line of code. I welcome any ideas regarding this goal.

thank