Photoshop and Mars Rover Curiosity "Earth Filter"

Great article on the Photoshop filter NASA uses to help geologist identify pictures of Martian Rocks. Need a Mars white balance card.
Even the most casual fan of space travel would notice something funny about the latest image from the Mars Curiosity rover, as seen below. I mean, they call Mars the "Red Planet" for a reason, and here we are looking at blue rocks.
http://www.theatlantic.com/technology/archive/2012/08/why-are-there-blue-rocks-in-the-latest-photos-from-mars/261149/