Hi. My name is Arielle Eckstut, and I am the author of What Is Color? 50 Questions and Answers on the Science of Color. Color is an incredibly difficult subject, one that encompasses all kinds of categories of science and history and culture – you name it.
But today in about five minutes I'm going to try to answer this question: What is color? And I'm going to do that by starting with yet another question. In the fall, do the leaves change color if no one is there to see them? Take a moment to think about that: Do the leaves change color if no one is there to see them? Now, the *obvious answer* to this question is "Of course they change color
because the color of the leaves are inherent to the leaves themselves." But in fact, that is not true at all, and the answer is a resounding *no*. If there is not a living being with a brain observing those leaves, the leaves do not change color. And the reason for this is that there's no such thing as color without the *eyes* and the *brain*.
So, different brains process visual information differently. And I realized that this idea that color does not exist outside of our perception can be very difficult to swallow. And in fact, our brains go to great lengths to give us all of the colors that we see.
The source of our color vision is in our *retina*, a credit-card-thin sheet of neurons in the back of our eyeballs. And it's actually a part of our brain, our retina. It's the only part of our brain that exists outside of our skulls. And our retina is what we typically associate with sight in general. If I were to ask you, "Why do we have eyes?" most people would say, "So we can see."
But that was actually not the original purpose of our eyes and our retina. The original purpose was to tell us when to be awake and when to be asleep. So, our eyes sensed when it was light out and when it was dark out, and "when" is the most important word here because our eyes, our retinas have three different systems:
the *when system* being the most primitive and the first use of our eyes. The next system is the *where system*, and that tells us where we are situated in the world. Are we right at the edge of a cliff? Are we too close to a potential predator? Or are we too far to reach a berry that is ripe that we would like to eat?
Lastly, we get to our *what system* – the system that designers deal with on a daily basis but the one that is actually *least important* to our visual system. The what system is the system that we use when we are *focusing on something*, whether that be a computer screen or a phone or a face or a road sign. It's also the system that we use to see color.
Color scientist Mark Rea has a great quote that I adore: "Color is a pigment of our imagination." And that really is true. Our imagination plays such a big role when it comes to color. And our brains are constantly taking in information from the outside world to help inform us about what time of day it is, where we are in the world, what we're looking at,
which really gets us to the next question, which is: Why do we see color to begin with?