Why Darker Colors Absorb More Heat Than Lighter Colors

Heat from the sun is absorbed by darker colors and reflected by lighter colors

Did you ever wonder why everyone wears lighter colors in the summertime and darker colors in the winter months? The answer may surprise you. It has a lot less to do with fashion than you think and everything to do with science.

Who hasn’t headed to a theme park as a child and been stopped by Mom because you had on your favorite black shirt? She sent you to your room to find a white t-shirt while telling you that you would feel cooler. Guess what, that wasn’t an old wife’s tale. Mom knew what she was talking about. It is all based on the science of energy, heat, and light.

Understanding Colors of Light

Objects absorbing and reflecting colors of white light

In order to understand why black is a warmer color, we need to understand why the color black and other colors look the way they do. The appearance of all colors are determined by which wavelengths of light are being reflected off of an object.

When you look at an object that is white, you are actually seeing all of the wavelengths of light being reflected back to you. White doesn’t absorb any light wavelengths. On the other hand, when you see a black object, you are actually seeing the absence of any light wavelengths being reflected back. Black absorbs all of the wavelengths of light.

So, how do other colors work? The colors you see are determined by which wavelengths of light are being reflected back to you. For example, when you see a red wagon, all of the light wavelengths that are hitting the wagon are absorbed except for the red wavelengths. These red wavelengths are being reflected back to your eyes. You then register the wagon as being red.

Absorption and reflection of light from different colors

Why Black and Other Darker Colors Are Hotter Than Lighter Colors

Now, back to our question of why the black shirt would be hotter than a white one. Think about that black shirt. It is absorbing all of the wavelengths of light. Once those wavelengths are absorbed, they are converted into other types of energy. This usually means that the light is changed into heat. Some of that newly created heat will be released back into the air, but most of it will be emitted directly to your body. The result is a feeling of being hotter.

Your white shirt is the better option to wear on a hot day because it will do the exact opposite of a black shirt. The white shirt will not absorb any of the light wavelengths. That leaves the shirt with nothing to convert into heat. The white shirt will then feel cooler against your body. Don’t expect to feel a chill while wearing white. While this science explains the idea of a white shirt feeling cooler, the humidity and wind will play a part in your comfort, and these have nothing to do with the color you choose to wear.

The Science Behind Color and Energy

Heat experiment with black, white and reflective tins of water. Black tin heated most, reflective least

Light and heat are both forms of energy. Light energy can change into heat. This backs up our previous explanation of why dark colors absorb more heat. Keep in mind that different wavelengths of light will have different amounts of energy. The amount of light energy a color absorbs determines the amount of heat energy that light can be converted into. For example, the color violet contains more energy than red. That means violet absorbs more light, making it a warmer color than red.

How a Color’s Shade Affects the Warmth

The amount of heat a color absorbs is also affected by the shade of a color. Let’s look at two shirts of the same color. Blue works well for this experiment. One shirt is a light powder blue. The other shirt is a dark navy blue. The darker shirt, even though it is the same base color as the lighter one, will absorb more light. This light changes to heat. The result is that the darker navy blue shirt will retain more heat and make you feel warmer.

Bright Reflective Colors and Heat

Protective reflective surface under the windshield of car keeps out heat

We refer to many colors as being bright. For example, yellow and pink are both considered to be bright colors. These bright colors reflect a larger degree of light wavelengths back to our eyes. Due to the fact that bright colors will reflect back so much of the light wavelengths, they absorb very little heat. This is why placing a reflective surface under the windshield of your car is so effective for blocking out heat from the sun. This is also a reason why your spring and summer wardrobe should include much brighter colors than your winter clothing.

How the Finish Changes Light Absorption

Once you start changing the sheen of a particular color, you are messing with the rules of light wavelength reflection and heat conversion. When you compare colors with a shiny or glossy finish to the same color in a flat finish, the light absorption changes. The shiny colors are able to reflect more light, even though they are the same color. Less light wavelength being absorbed means less heat is generated. Even darker colors like navy blue and hunter green will hold less heat if they have a glossy finish. As long as all of the colors you are working with have the same sheen, the brighter colors will always be cooler.

Listen to Mom

Teen in white shirt cooling down with an ice cream in a theme park

So, when it comes to wearing that white shirt to the theme park on a hot summer day, listen to Mom. She knew what she was talking about, and science will back up her theories. That black shirt will absorb the light and turn it into heat that will make you uncomfortable, but don’t use this knowledge for clothing alone.

Now that you understand why darker colors absorb more heat than lighter colors, you can use this knowledge in many areas of life. Homeowners have long known that black shingles and dark colors are best used in northern areas that experience cold winters, while white siding and light gray roofs are a blessing in tropical climates.

You might also apply this information to buying a vehicle. While a white car, truck, or SUV is harder to keep clean, the cab of the vehicle will heat up much faster in a black automobile than a white one. Never underestimate the power of darker colors absorbing more heat than lighter shades.