There seems to be a little bug that affects a small number of MacBook Pro (with dual graphic card) machines; the display would turn blueish when the discreet graphic is in use by way of the Automatic Graphic Switching.
User daywalkerdha shared a fix, but I’ve included some extra steps to ensure its effect:
- Close all running apps, unplug the power cable.
- Disable automatic graphics card switching while in battery-mode (in System Preferences).
- Reboot, and reset the PRAM (Hold Option-Command-P-R keys, continue until second startup time).
- Connect the power cable after the boot sequence finish.
- Enable automatic switching again.
Update: The same problem reappears in Yosemite (build 14A261i), and the same fix seems to have worked accordingly.