A simple open source app to change to color of a calendar in android 4+. Tested with calendars provided by baïkal.
The color is slightly different from what the google calendar app is showing. The google calendar app seems to tweak the colors a little bit. Colors set in owncloud are also slightly different in the google calendar app.
The color changes back after some time Many calendar services will overwrite the color when syncing. Set the color directly in the service (e.g. google, owncloud) instead.
HoloColorPicker - https://github.com/LarsWerkman/HoloColorPicker