## Monday, November 14, 2016

In the Spring 2016 issue (#474) of ISCC News, I described what appeared to be a paradox that emerged from an exercise for students [1]: “If the wavelength of the green line of mercury is 546 nm in a vacuum, what is it in water? In heavy flint glass? [410 nm, 331 nm].” Would change of refractory material abutting the eye’s photoreceptors cause the color of a light to change as drastically as suggested here? More precisely, would changing the refractive index change the tristimulus values of a light with emitted spectral power distribution E(λ)?

Unlike in the wavelength domain, the change of refraction index would not affect the frequency of the transmitted light. I concluded that the proper choice of integration domain in which to perform tristimulus integration should be a matter of experiment.  This conclusion was incorrect. As often happens when one poses a paradox, closer examination provides a resolution. The tristimulus values should not change if the integrals are performed properly.  I describe the resolution in a tutorial note recently posted for publication in Color Research and Application [2].

It is reasonable and respectful of physical principles that a tristimulus value [say, M = the integral over λ of  E(λ) m(λ)] should not depend on the domain of integration used to obtain it. In [2] it is shown that the domain invariance from wavelength λ to frequency ν = c/λ is assured if the spectral power distribution of the test light in frequency is represented as E*(ν) =|dλ/dν| E(λ(ν)).

Now imagine a transformation from frequency to two alternative wavelength domains λ1 = c1/ν  and λ2 = c2/ν , where c1 and c2 represent speeds of light in different refractive indices (possibly functions of ν ).  Here, M doesn’t change either; rather, the spectral power distribution E*(ν) is multiplied by the Jacobian |dλ1/dν  |-1 or | dλ2/dν |-1, respectively. (Things get a bit more complicated when λ1 or λ2 is a nonmonotonic function of ν , but the principle is the same.) Of course, changing from λ1 to λ2 is equivalent to changing from λ1 to ν  and then from ν  to λ2.  There is no predicted variation of M, by construction.

So my “gentle paradox” evaporates by construction. Obeying the rules of mathematics leads back to where one started: tristimulus values don’t depend on the refractive index of the transmitted medium.

Where does that leave the role of experiment? If one were to measure the camera version of tristimulus values in different refractive media (say, with M being a measured camera value for a light E through a camera sensitivity function m), we would expect no change in those values.  But experiment can trump theory. If M were observed to change, then a new paradox would surface. From “paradox lost” we would see “paradox regained.”

References:
[1]. HQ Fuller, RM. Fuller, and RG Fuller, Physics Including Human Applications. Harper and Row, 1978. Revised electronic version copyright 2009 by RG Fuller. http://physics.doane.edu/hpp/Resources/Fuller3/pdf/F3Chapter_19.pdf exercise 2, p. 436.
[2] MH Brill, Ways to define a tristimulus value. Color Res. Appl. 2016, Early View, DOI 10.1002/col.22079.

Michael H. Brill
Datacolor

## Thursday, August 4, 2016

### From Color Science to Privacy

[Here is the latest word from Michael Stokes, architect of sRGB, a founder of ICC, Interest Group II chair of ISCC, …, and ten years absent from the field of color.]

I grew up in my family’s slide duplication and photofinishing business back when E4 processing was still new, and Kodachrome, FujiChrome and AgfaChrome were widely available. The business grew to the point my parents bought entire emulsion runs of motion picture and inter-negative stock from Kodak to ensure consistent quality. Our computer system tracked every action taken of each slide or component of each order, and we offered an unconditional money-back guarantee. I was responsible for the quality and production aspects of the business, so I spent what seemed like endless time trying to understand why it was so difficult to craft color reproduction processes that were consistent and accurate.

In the late 1980s, I joined RIT’s Color Science Master’s program and soon my frustration transformed in wonder and awe that we were able to reproduce color reasonably well given the many complex aspects involved. I was fortunate enough to have a successful color career at Apple, then at Hewlett-Packard, and finally at Microsoft as their Color Architect. Over this period, I helped to lead industry efforts such as the founding of the ICC, standardization of sRGB and scRGB, evolution of ColorSync and ICM, as well as taking part in the founding of CIE’s Imaging Science Division. I often explained the goal of my efforts as trying to reverse engineer a large part of the human brain to effectively model it across a complex system of components from many stakeholders who didn’t always get along with each other.

I joined Microsoft in 1999 in hopes of implementing the best-in-class color reproduction software development systems. By 2006 we had successfully implemented advanced hybrid solutions that supported sRGB, scRGB, and ICCv4 as well as CIECAM color vision modeling. This was a part of Windows Vista, which was known to have significant challenges.

It soon became clear that advanced color systems were not the most pressing need for the company, and I transferred to Microsoft’s newly established Health Solutions Group (HSG). As part of this transition, the company required that I no longer participate in the color field and have no communications regarding color with my many friends and colleagues that I had established over many years. It was a difficult personal decision, but in the end, I chose to put my family’s financial stability first. I am sincerely and deeply sorry for the negative impact this has had on my communications and relationships with many dear color friends and colleagues.

My original job description focused on health standards and patents, in which I had significant experience from my color science background having worked with IEC, CIE and ISO as well as accumulating over 50 patents. Within two weeks, my role grew to include a focus on security and privacy. I had security experience having designed and written color and imaging components in the Windows kernel software. Privacy was completely new.

It turns out that privacy is very much like color reproduction. The goal is to understand human desires and perceptions around information data flows, controls, and ownership to effectively model these desires and perceptions across a complex system of components from many stakeholders who don’t always get along with each other, including regulators, legislators, and consumer advocates.

I was again extremely fortunate to enjoy a second successful career, including testifying before the US Senate Judiciary Committee, visiting numerous national and international regulators including the US Food and Drug Administration, US Federal Trade Commission, and CNIL  (French Data Protection Authority).

When Microsoft divested HSG into an independent subsidiary jointly owned by General Electric (and now wholly owned by General Electric), I again chose to put my family’s financial stability first and stay at Microsoft. I now help manage privacy for many of Microsoft Office client applications including Word, Excel, PowerPoint and OneNote among others. I believe I have one of the best jobs in the company, helping design architectures and processes to empower our users to best achieve their desires.

The major regret I have had in my career was not being able to explain why I “went dark” from all of my color friends. I hope this article sheds some light on those difficult days and deeply appreciate the opportunity that ISCC has provided me. I know I owe two successful careers to my friends and colleagues in color science who taught me so much about color, and even more about life.

Thank you,
Michael Stokes, mistokes-color@outlook.com

## Tuesday, May 3, 2016

In my recent web-browsing, I ran across an exercise for students [1]: “If the wavelength of the green line of mercury is 546 nm in a vacuum, what is it in water? In heavy flint glass? [410 nm, 331 nm].”

This awakened me to a question I have not seen posed by color science. Would the color of a light change as drastically as suggested by the wavelengths in the above paragraph? [Strictly speaking, of course, the waves have no intrinsic color, but I use loose terminology for convenience, with the understanding that the only meaningful connection is a cetera paribus color match.]

The effect of wavelength shift would depend upon the context. Surely placing a piece of flint glass in air between a mercury-line lamp and a human viewer would not influence the wavelength of light arriving at the eye. Although the wavelength 546 nm would change to 331 nm while the light was within the glass, it would change right back to 546 nm as soon as it re-entered the air. Then it would change to its value of 410 nm upon entering the aqueous medium of the eye and photoreceptor system. (Of course, the light’s frequency would always be the same.) But we wouldn’t notice any change due to the 546-to-410 nm transition because we always see through the same aqueous medium (with the same refractive index) embedding the photoreceptors. 546 nm as measured by a spectroradiometer is hence calibrated to be identical to 410 nm as incident on our photoreceptors.

But suppose we change the refractive index of the material abutting the eye’s photoreceptors and see if the color of the refracted light changes. Even though abutting the photoreceptors with a non-waterlike substance seems impossible with real eyes, it is an option with cameras whose photosensors are embedded in the chosen refractory material; also, visual prostheses in the future could have this option.

So, under these circumstances, would the color of a light change as drastically as suggested by the wavelengths recited in [1]? If the color did not change, then for this weird situation one should compute tristimulus values with frequency rather than wavelength as the integration variable: light does not change frequency when passing through a transparent medium. Perhaps someone has already tested the idea with cameras. I await the impact of the idea once prosthetic eyes are abundant.

References:
[1]. HQ Fuller, RM. Fuller, and RG Fuller, Physics Including Human Applications. Harper and Row, 1978. Revised electronic version copyright 2009 by RG Fuller. http://physics.doane.edu/hpp/Resources/Fuller3/pdf/F3Chapter_19.pdf exercise 2, p. 436.

Michael H. Brill
Datacolor

## Monday, February 8, 2016

### Think Pink

Rose Quartz may be Pantone’s 2016 color of the year (along with pale Serenity blue), but pink has been steadily emerging as a color of influence for many seasons.

Pink is inherently warm and gentle, combining the passion of red with the purity of white. Research suggests that the color elicits a calming physiological response [1]. Accordingly, it has been employed in prisons and hospitals to create a soothing atmosphere.  [Note: Other research [2] suggests that the effect of pink on behavior in prisons may be an artifact of the “Hawthorne Effect”, whereby prisoners react to a newly painted cell---irrespective of color---only for a while until the newness wears off.]

Based in part on its mixed parentage, it has come to represent diversity.  Specifically, the color’s arc strongly correlates with key societal trends surrounding gender issues.  From as recently as the early 20th century, pink was a color ascribed to males. Social trends – and possibly Nazi politics – created a pendulum swing, and by the 1940’s, pale pink had come to be associated with the fairer sex – particularly for babies.  Innovative designers such as Elsa Schiaperelli helped bring the shade into fashion for women with the brand’s signature color,  “shocking pink”. In the 1950’s pink had clearly become associated with women. It was prescribed as distinctly feminine, reflecting the rigid society norms of the time toward gender roles.

The color continued to hold favor with women through the 1960’s into the early 1970’s, an era fuelled by women “libbers” who were taking charge behind the wheel of their pink-tinted Mary Kay Cadillacs. Surprisingly, pink found a way to bridge the gap between the housewife and the emancipated woman. A desire for brilliant, strong color dominated in the 1970’s and 1980’s and pink fell dormant. Women were concerned with looking serious and professional and the association with the softer side of femininity meant the color took a back seat during this period.  As the 1980’s came to an end, defined gender roles began to shift and neon pink and magenta were adopted for their high impact personalities.

Pink entered the fashion realm once again in the late 1990’s. In 1999, Gwyneth Paltrow sparked a trend on the red carpet, donning a pale bubblegum Ralph Lauren gown to the Academy Awards. She repositioned the color as cool, extricating it from its association with little girls.

Haute Couture has continued to follow suit. Recent examples include designer Raf Simons statement-making runway show in the Fall of 2012 for Italian luxury brand Jill Sander. For his final collection with Sander, Simons combined pink in all tints and tones. It was a wonderful celebration of the hue and further propelled the color into the public realm.

The recent popularity of Apple’s rosy iPhone 6s is another indicator of the hue’s burgeoning popularity. Straying from the electronic industry’s penchant for neutrals, Apple carefully veiled the introduction of its pink tone under the guise of “rose gold”.  But, anyone who has seen the gadget can attest to its blatant metallic pink appearance. Regardless of its title, the color has seen great success - among both women and men - garnering the longest wait lists of all the 6S hues.

Food and beverage trends have also not been immune to pink’s resurgence. Rosé sales have been on a steady incline. In the summer of 2014, there was a shortage of the pink wine in “the Hamptons,” New York’s trendy holiday region .  As a direct result, millennial social media icon Josh Ostrovsky, who goes by the handle @TheFatJewish, launched his own line of wine calling it “White Girl Rosé”. Despite its non-pc name, the company has done exceedingly well, launching a rosé craze that has crossed into fashion, including the creation of a pink clothing line emblazoned with quips about rosé by Wild Fox Couture.

Women have once again embraced the color across the board – and this time it includes the workforce.  As women have asserted their position in the workforce (and beyond), they have become confident in their identity, celebrating individuality and creative spirit. Instead of rejecting classically feminine colors, people are embracing them.

The hard and fast rules have lifted, and men, too have reclaimed a taste for this tint of red. Pink has come to symbolize a neutrality between the sexes. A societal shift is underway; softening boundaries that one could argue blur the lines of gender and outdated roles for males and females. Pink has become an extension of this movement. It is, in a sense, the perfect color to represent this time of change, with its gender-flipping history and chameleon-like character.

There appears to be no sign of the color fading, and, as such, it would be wise to take advice from the infamous Funny Face fashion editor, Maggie Prescot, and “think pink!”

Roseanna Roberts, roseannaroberts.com
CAUS and color trend consultant

Roseanna Roberts has over 10 years’ experience in color development and trend analysis. She has worked in many of the world's creative epicenters, including London, Toronto and Melbourne. Since moving to New York in 2010, she has worked as the director of color trends at The Color Association of the United States. Roberts continues to work with CAUS, as well as providing customized expert insight to corporate brands as a color trend consultant. Roseanna@roseannaroberts.com / roseannaroberts.com

[1] Schauss, A.G.: Tranquilizing Effect of Color Reduces Aggressive Behavior and Potential Violence (1979). Journal of Orthomolecular Psychiatry 8,218-220,1979.
[2] Pellegrini, R., Schauss, A.G., and Miller, M. E. (1981): Room color and aggression in a criminal detention holding cell. A test of the “tranquilizing pink” hypothesis, Journal of Orthomolecular Psychiatry 10 (3), 174-181, 1981.