Can one small difference on a package make a difference in how you perceive the healthfulness of a food??

Think we're rational decision makers? Check out this post from Fooducate:
Take a look at the candy bars above. They are identical except for one small detail in their packaging. The front of pack calorie label is red on one wrapper, green on the other. Obviously there is no difference.

But in a study conducted on close to 100 students at Cornell University, in which they were shown just one of the wrappers, students tended to think that the green labeled candy bar was healthier than the red labeled one. Just another little marketing trick that will no doubt increase sales by a few millions of dollars…

By the way, the current packaging for Twix candy bar is below. Did you notice the color of the calorie information on the bottom left?