In a physical sense, there really is no such thing as color, just light waves of different wavelengths. The human eye can distinguish among these wavelengths, so we see the world in color. Rays of light vibrate at different speeds. The sensation of color, which happens in our brains, is a result of our vision's response to these different wavelengths. When taken together, the various rays our eyes can distinguish are called the visible spectrum. This fairly narrow range of colors includes red, orange, yellow, green, blue, blue-violet (which scientists call indigo), and violet.

Color is basically very important in design. It helps convey mood, draw attention, and communicate without words. Designers must consider how colors behave across different mediums, how they affect readability, and how they make people feel. Understanding concepts like hue, tone (value), saturation, and temperature helps create more effective and meaningful designs.