Here are images I created to demonstrate how the iPhone calendars could have options.
Here is the original screen.

I added a new “Edit” button.After touching the Edit button, the circles on the right show up.Selecting an individual calendar temporarily displays the check mark before moving on to the next screen.In this screen, there is the name of the calendar, a “Done” button, a “Display with All” toggle, and a color selection bar. The “Display with All” toggle will include the individual calendar when viewing all calendars when the toggle is set to “On”. Setting this toggle to “Off” means that this individual calendar is only available in the individual view mode. At first, the current color is designated by a circle. The circle shows more clearly on the iPhone.After selecting the new desired color the selection circle will move to the designated color. The user will then touch the “Done” button to be brought back through the menu.