This new mode will allow players who are affected by deuteranopia (red-green colorblindness) to better distinguish between friendly and enemy health bars and spell effects during gameplay.
To give you a better idea of what an improvement this will be for the gameplay experience of these players, check out the below screenshots for a peek at what the game looks like for red-green colorblind players before and after the switch to Colorblind Mode.
How to use Colorblind Mode?
While in game hit your 'Esc' key and you will pull up the options menu. Click the 'Video' tab:
Next click 'Colorblind Mode' under the Resolution: