Why does red absorb more light?
Colour of objects
The colours we see are the wavelengths that are reflected or transmitted. For example, a red shirt looks red because the dye molecules in the fabric have absorbed the wavelengths of light from the violet/blue end of the spectrum. Red light is the only light that is reflected from the shirt.
The specific order from least to greatest amount of heat absorption is: clear, orange, yellow, red, green, purple, and blue. In conclusion, darker colors will warm up more quickly and absorb more heat in sunlight than lighter colors.
A red pigment is capable of absorbing cyan light. That is, red paper can absorb both green and blue primary colors of light (recall that cyan light is a mixture of green and blue light). So red and green light shine on the paper; and green light is subtracted.
Black objects absorb all the light shined on them. There is no reflected light, so we see black (the absence of color). If all of the light is reflected, we see all the wavelengths, which means we see white light.
Red light has relatively long waves, around 700 nm long. Blue and purple light have short waves, around 400 nm. Shorter waves vibrate at higher frequencies and have higher energies. Red light has a frequency around 430 terahertz, while blue's frequency is closer to 750 terahertz.
Vantablack (Vertically Aligned Nanotube Array BLACK) can absorb 99.965 percent of ultraviolet (UV), visible and infrared (IR) light. British researchers at Surrey NanoSystems helped developed the material, and its properties can be used on telescopes as well as making objects seemingly disappear.
The more light the object absorbs, the more heat absorbed since light is energy. If you consider it a color, black absorbs the most heat. A black object absorbs all wavelengths of light and reflects none. Objects that are white, on the other hand, reflect all wavelengths of light and therefore absorb the least heat.
Red objects reflect red light, green objects reflect green light, and so on. But what happens to the rest of the colors that hit that object? They get absorbed! If you have a red object, all the orange, yellow, green, blue, and violet light gets absorbed into that object.
Red has the lowest energy and violet the highest. Beyond red and violet are many other kinds of light our human eyes can't see, much like there are sounds our ears can't hear. On one end of the electromagnetic spectrum are radio waves, which have wavelengths billions of times longer than those of visible light.
Red. Red attracts the most attention and is associated with strong emotions, such as love, passion, and anger. It's the universal color to signify strength, power, courage, and danger. Red is vibrant, stimulating and exciting with a strong link to sexuality and increased appetites.
Does red absorb all colors?
However, I learned that if something is red, it is absorbing all/most colors except red. Our eyes are seeing the wavelength of red reflected from (say) a red shirt, which is cotton with red dye. So, this red dye is "reflecting" red light, and "absorbing" everything else.
Red has the longest wavelength of visible light, so it has the lowest energy. Violet light has the shortest wavelength, and so it has the highest level of energy of visible light.

Pure white, being the most reflective color, is at the other end of the scale at 100 because it doesn't absorb light or warmth. Colors that fall below 50 on the LRV scale will absorb more light than they reflect. Shades above 50 help create a daytime look and add a feeling of expansion to a space.
The world's darkest black absorbs more than 99% of visible light | Freepik Blog.
Color. When atoms or compounds absorb light of the proper frequency, their electrons are excited to higher energy levels. Colored compounds absorb visible (colored) light and this absorption is responsible for their color.
Chlorophyll absorbs light in the red region. Because red light has the highest absorption by chlorophyll, it is the most effective wavelength for photosynthesis.
In our case of visible light, the highest frequency color, which is violet, which means it will have the highest energy.
It absorbs certain wavelengths of light within the visible Light Spectrum. Green color light is not absorbed but it's reflected well for making the plant appear (Green).
Color absorbed | Color seen |
---|---|
Blue | Orange |
Green | Red |
Yellow | Violet |
Orange | Blue |
Red objects reflect long wavelengths of light (and absorb shorter wavelengths), while blue objects reflect short wavelengths of light (and absorb longer wavelengths). Black objects absorb all visible wavelengths about equally, and white objects reflect all visible wavelengths about equally.
How does color affect light absorption?
Darker colors absorb more sunlight than lighter colors, which is why darker colors get warmer more quickly in the sunlight than lighter colors. The lighter colors reflect more of the sun's radiant energy, so they remain cooler to touch in the sunlight.
With a longer path length, the light has to travel through more solution, and can hit more molecules, and be absorbed. This would make the aborbance increase and have less light transmit through makeing the solution appear darker.
Thus, a “red” object is absorbing all other wavelengths, and reflecting or allowing to pass through only the red wavelength. Whether it 'reflects' or 'adsorbs' is just a matter of the perspective of the viewer – whether the light source is in front of it, or behind it.
Colored objects, on the other hand, reflect back only some of the wavelengths; the rest they absorb. For example, if white light shines on a red ball, the ball reflects back mostly red light, and so we see red.
colour* | wavelength (nm) | energy (eV) |
---|---|---|
red | 650 | 1.91 |
orange | 600 | 2.06 |
yellow | 580 | 2.14 |
green | 550 | 2.25 |
Red light has a longer wavelength, a smaller frequency, and thus a photon energy which is smaller than blue light.
Violet has highest energy.
The sun emits energy in the form of electromagnetic waves. We see part of the electromagnetic wave as light and we feel part of it as warmth. Darker colors absorb more sunlight than lighter colors, which is why darker colors get warmer more quickly in the sunlight than lighter colors.
Plant pigment molecules absorb only light in the wavelength range of 700 nm to 400 nm; this range is referred to as photosynthetically-active radiation. Violet and blue have the shortest wavelengths and the most energy, whereas red has the longest wavelengths and carries the least amount of energy.
RED shirt absorbs all the wavelengths except for RED (so, the white lights must be emitting some Red light). BLUE shirt absorbs all the wavelengths except for BLUE (so the white lights must be emitting some Blue light).
What color of light would a red shirt absorb the best?
RED shirts absorb all the wavelengths except for red (so, the white lights must be emitting some red light). BLUE shirts absorb all the wavelengths except for blue (so the white lights must be emitting some blue light).
Light colored clothing reflects most of the visible wavelengths which, in turn, absorbs less heat. On the contrary, darker or black clothing absorbs more wavelengths, absorbing more heat, hence making the clothing warmer to wear.
Absorbance measures the amount of light with a specific wavelength that a given substance prevents from passing through it. The two main factors that affect absorbance are concentration of the substance and path length.
Color. When atoms or compounds absorb light of the proper frequency, their electrons are excited to higher energy levels. Colored compounds absorb visible (colored) light and this absorption is responsible for their color.
Light energy can be converted into heat energy. A black object absorbs all wavelengths of light and converts them into heat, so the object gets warm. A white object reflects all wavelengths of light, so the light is not converted into heat and the temperature of the object does not increase noticeably.
The wavelength of blue light is 475 nanometers while the wavelength of red is 650 nanometers. BLUE light carries a higher energy signature then RED light does and that higher energy with a shorter wavelength should provide the plants with a better environment for growth.
Ranging from 600-700 nm, red light wavelengths encourage budding and flowering. Along with blue light, red light wavebands are considered one of the most important for photosynthesis and biomass growth. Indoor growing environments typically use a balanced combination of red and blue light for best results.
Red light. It's thought that colors close to red on the light spectrum might stimulate melatonin production.