Turn on/off any individual calendar regardless of its color group.

Pease allow us to turn on/off any individual calendar regardless of its colour "group"

Forcing users to turn off calendar in groups based on their color might work fine for people who only have a couple of calendars, but if you have many calendars this behaviour makes the app unmanageable. In my case it makes the app unusable because I have 40 calendars. Being forced to manage color groups, just to control visibility is a huge overhead for no advantage.

My suggestion for the pull down menu where the visibility of the calendars are toggled: 

- have a checkbox next to each calendar in the menu list

- you could still sort the list in the menu by colour, but don't group them