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What is the most whitest Colour?

What is the most whitest Colour?

The search for the whitest color is an interesting one. When we think of “white”, we often imagine pure white light or snow. However, from a technical perspective, different shades of white have subtle differences in brightness and color temperature that make some “whiter” than others.

In this article, we’ll examine the science behind perceiving color, look at how white is defined, and determine which white colors could potentially be considered the “whitest.” Understanding what makes something the whitest white requires an understanding of the physics of light and color.

How We Perceive Color

Human color perception is controlled by specialized receptor cells in our eyes called “cones.” There are three types of cones that are each sensitive to different wavelengths of light:

– Short wavelength (S) cones that detect blue hues
– Medium wavelength (M) cones that detect green hues
– Long wavelength (L) cones that detect red hues

These cones send signals to our brain that are interpreted as color. When all three cones are stimulated equally, we perceive white. This is why white light contains a balanced mixture of all wavelengths of visible light.

Our perception of how white an object is depends on a few factors:

– The object’s albedo – how much light it reflects vs absorbs
– The color temperature of the illumination source
– Surrounding colors due to contrast effects

Objects with a perfectly even, neutral reflectance spectrum and viewed under evenly balanced white light will appear maximally white.

Defining White

There are a few ways we can define the “whiteness” of a color:

– **Brightness** – The total amount of light reflected. A perfectly reflecting white would be 100% brightness.

– **Saturation** – How devoid of hue a color is. The less saturation, the more white.

– **Color temperature** – The relative color balance of light sources. Higher temperature light appears more blue/white.

– **Reflectance curve** – How evenly a surface reflects all visible wavelengths.

So in summary, the “whitest” color would be a maximally bright, neutral white with an even reflectance curve when viewed under a high color temperature illuminant.

Whitest Natural Whites

If we look at natural white materials, a few stand out as contenders for the whitest white:

– **Fresh snow** – The wide crystalline structure of fresh fallen snow reflects visible light extremely well. Its albedo can reach up to 0.9.

– **White marble** – A metamorphic rock made mostly of calcite with trace impurities. High purity marble can appear extremely white.

– **White sand** – Made of silica (silicon dioxide), white sand beaches in tropical areas with coralline sources tend to be very white.

– **White clay** – Kaolin clay deposits found in humid regions can form very white hydrous aluminium phyllosilicate rock.

– **Bird plumage** – Some birds like the white stork have feathers that produce very high reflectance whites, due to microscopic air bubble structures.

So in the natural world, fresh snow, high purity marble/limestone, white sands, kaolin clay and some bird plumage likely represent the whitest examples. Exact quantification and comparison is difficult.

Whitest Manmade Whites

Artificial materials and coatings have also been engineered to create ultra-white surfaces and pigments by optimizing reflectance:

Material Description
Titanium white pigment Made from titanium dioxide nanoparticles with high refractive index.
Zinc oxide A wide bandgap semiconductor used as a white pigment and sunscreen ingredient.
Magnesium oxide An inorganic white hygroscopic compound used as a pigment.
Calcium carbonate Abundantly used as chalk, limestone, and marble white pigment sources.
Barium sulfate A white insoluble sulfate used as pigment for photo paper and cosmetics.

Specialized ultra-white paints have also been produced using optimized particle sizes and UV-reflective components:

– Vantablack – A vertically aligned carbon nanotube coating that absorbs up to 99.9% of light.

– Ultra-white paint – Using barium sulfate and titanium white pigments, this paint reflects up to 98.1% of visible light.

– White 3.0 – A calcium carbonate-based paint claimed to be the “whitest white” at high color temperatures.

Whitest Light Sources

For illuminants, bluer color temperatures tend to appear whiter:

– Clear blue sky – Scattered blue light gives the sky a white appearance with color temps of 10,000K or higher.

– Midday sun – Direct sunlight reaches up to 5,300K.

– LCD displays – Can mimic white points from 2,000K to over 10,000K.

– LED lighting – Variable color temperature LEDs can create crisp whites up to 6,500K.

So the bluest natural or artificial light sources generate the whitest illumination. Interestingly, our eyes perceive higher color temperatures as more white, even though the spectrum is less evenly balanced.

Whitest Visual Illusions

Optical illusions can also trick our eyes into perceiving white. Some examples:

– Simultaneous contrast – Surrounding a gray with blue makes it appear warmer and whiter.

– Afterimages – Staring at a bright image leaves an inverted “afterimage” that appears whitish.

– Mach bands – The boundary between gradients appears to have sharper contrast, enhancing white.

– Color mixing – Spinning color wheel toys use persistence of vision to mix colors into white.

So while not actual sources of white light, optical illusions take advantage of the eye’s color processing to simulate extremely white looking effects.

Measuring Whiteness

There are a few colorimetric scales used to quantify the measurement of white:

– CIE Whiteness – Accounts for color temperature and brightness. Fresh snow is considered the reference at 100.

– ASTM E313 Whiteness – Measures visible reflectance 400-700nm. Higher numbers are whiter.

– TAPPI Brightness – A pulp and paper industry whiteness standard.

– Hunter Lab – Can calculate L,a,b color values where L=100 is perfect white.

– CIE L*a*b* – L=100 is also perfect white on this universal color space.

These metrics allow different white materials and light sources to be quantified and compared. Fresh snow, high purity magnesium oxide, and sunlight rate among the highest.

The Whitest Whites

Based on all the above information, what are some of the whitest white examples across different categories?

– **Nature**: Fresh snow, white marble, chalk, limestone

– **Manmade pigments**: Titanium white, zinc oxide, magnesium oxide

– **Paints/coatings**: Ultra-white paint, Vantablack, White 3.0

– **Light sources**: Blue sky, midday sunlight, high CCT LEDs/LCDs

– **Optical illusions**: Simultaneous contrast, afterimages, color mixing

So while fresh snow probably takes the title for the whitest natural white, specially engineered paints and coatings using titanium dioxide, barium sulfate and other pigments may have achieved even higher technical whiteness. Blue-shifted daylight illuminants also appear extremely white to our visual perception.

Conclusion

The quest for the “whitest white” is not straightforward, as there are several ways to characterize whiteness based on reflectance curves, color temperature, brightness, and purity. Fresh snow and purpose-engineered paints/coatings rank among the whitest examples in nature and those created by humans. Blue-shifted natural and artificial light sources also appear strikingly white. Whiteness is truly in the eye of the beholder, as optical illusions can trick our visual system into perceiving whites whiter than what light spectrum measurements might indicate. But with the right combination of highly reflective materials and bluish illumination, it is possible to create white environments and objects that live up to the highest standards of whiteness.