This post is primarily a reminder for myself on how to purge/reset the ColorSync user cache in order to fix the blue tint experienced when my macbook pro automatically switches graphics.
I’ve got a 2010 17″ MacBook Pro, which has both an integrated GPU (Intel HD) and a dedicated GPU (NVidia Geforce GT 330M). It “dynamically” switches between the two on-demand, which means some applications (e.g. Adobe Photoshop, Google Chrome) trigger the switch.
Since the upgrade from Snow Leopard to Mountain Lion, and now to Yosemite, when the MBP switches from the internal GPU (iGPU) to the dedicated GPU (dGPU), the screen would change colour. It would change from its correct colour to a somewhat blue-ish tint. Very annoying, especially when using Photoshop.
After googling around a lot, a number of posts on the Apple Discussions pages recommend gfxCardStatus, which allows you can “lock” the MBP on the iGPU. I consider this a bad option, since the dGPU is far more powerful than the iGPU and often you need that power.
I finally found a recommendation to reset or purge the ColorSync user cache. After trying this fix, and rebooting the MBP, it immediately worked, removing the blue-ish tint from the MBP screen when starting Photoshop or Chrome.
Step 1 – Open the Terminal.app
Either start typing
Terminal in the Spotlight search, or goto Applications > Utilities > Terminal.
Step 2 – Remove the ColorSync cache file
Terminal window, enter the following command:
sudo rm $(getconf DARWIN_USER_CACHE_DIR)com.apple.colorsync.profiles.`id -u`
Type your user password when prompted.
Step 3 – Finish
Restart afterwards and the screen will maintain the same colour on both the iGPU and the dGPU.
I don’t know why or how the ColorSync user cache gets corrupted, but I do know how to solve it!