Color why we see it
Think about your favorite brands — their logos and imagery are all carefully selected to incite specific buying habits and make you associate particular traits with the company.
When it comes to products, color can make us more attracted to an item. Bright candies are colorful and fun , while a ripe red tomato may look particularly fresh and juicy. Many manufactured products need to maintain the same color throughout production, to increase buyer confidence or improve identification. For instance, each pill of a specified drug must match the one from before it, and each can of paint should be mixed to the expected color.
The physics of color perception involves energy wavelengths, reflections and signals zapping back and forth in our brains. So what is color in science terms? Red has the longest wavelength, while violet has the shortest. As sunlight — which is a combination of all wavelengths — hits an object, some materials will absorb specific wavelengths.
This reflected light then reaches our eyes and makes us perceive the reflecting object as being a particular color. It involves the stimulation of rods and cones, which send a signal to the brain of what color we perceive. Cones and rods are activated by different types of colors and lighting scenarios. Due to variations from person to person and differing environments, the perception of color can vary wildly. Cones are stimulated in brighter environments.
Most of us have about 6 million cones, and million rods. Cones contain photo pigments, or color-detecting molecules. Humans typically have three types of photo pigments—red, green and blue. Each type of cone is sensitive to different wavelengths of visible light. The cones then send a signal along the optic nerve to the visual cortex of the brain.
The brain processes the number of cones that were activated and the strength of their signal. After the nerve impulses are processed, you see a color— in this case, yellow.
Your past visual experiences with objects also influence your perception of color. This phenomenon is known as color constancy. Color constancy ensures that the perceived color of an object stays about the same when seen in different conditions. As a result, businesses are turning to mathematical equations to specify colors , and non-subjective measuring devices to ensure precise matching. Many other color spaces have been defined. Measurement depends on colorimeters or spectrophotometers that provide digital descriptions of colors.
For instance, the percentages of each of the three primary colors required to match a color sample are referred to as tristimulus values. Tristimulus colorimeters are used in quality control applications. Controlling colors despite unavoidable differences in human perception starts with awareness and education.
TThankfully, there is a range of tools available to ensure the colors of your products are always accurate. Datacolor offers a complete line of spectrophotometers , software and other solutions suitable for a variety of industries—including plastics, textiles, coatings and retail paint.
We also designed an instrument specifically to measure materials that a traditional spectrophotometer cannot measure. Contact our team to discuss how the right color control solutions can help your team overcome the limitations of of color perception, increase quality and reduce costs. This website uses cookies and other tracking methods so that we can provide you with the best user experience possible.
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If you decided to turn off these cookies some parts of the site might not work properly. As it turns out, this is quite uncommon since most molecules absorb light above the visible spectrum, in the ultraviolet range. So, because electrons in most molecules are bound very tightly, most compounds are white! Some substances have electrons in the right range of binding strength which makes them suitable to use as dyes.
One of the first natural dyes is indigo, commonly used to colour jeans. The problem with indigo and other organic dyes is that it fades away in time because it absorbs energy, instead of reflecting it. In time, bonds break as a result of the damage. Inorganic dyes like pure iron oxide or rust ochre , however, are lightfast and can last for thousands of years.
This is why cave paintings are still visible today! As a conclusion, things do not have color by themselves — only when light energy hits them, we can see colors. Also, remember our eyes can only see a limited range of colours. But dogs, cats, mice, rats and rabbits have very poor colour vision. Evolution led bees to adapt ultraviolet vision because flowers leave scatter ultraviolet patterns, allowing the insects to easily identify targets and pollinate.
This is what spectrometers are for. Tibi is a science journalist and co-founder of ZME Science.