Directly opposite our eyes at the very back of the brain is the occipital lobe, where we process sight information. (Were we meant to have eyes in the back of our head?) Other than its obvious role in transforming the pops and clicks of electrical stimulus from our eyes into goodies recognizable by our consciousness, the occipital lobe stores the color tags associated with memories. Researchers showed this by presenting subjects with shapes—some colored and some not—and then asking subjects to remember the colors of the various shapes. PET scans showed their occipital lobes crackling when they remembered colored shapes; not so when they remembered the uncolored shapes.
Damage to the occipital lobe can result in its including bits of misinformation with the material it sends to our consciousness. We call these hallucinations.