OBS! Mobil detection was added to this release of Colorbox and it's on by default, i.e. Colorbox will not be active on small screens (mobile phones) by default. I personally don't think modals belong on small screens and therefor I made this choice.
If you really need/want to reactivate Colorbox on small screens go to "/admin/config/media/colorbox" under "Advanced settings" after updating to this version and turn of mobile detection.