A Cloudy Kind of Sunshine

My Pantone-influenced hiking boots on a rare sunny day

The title of this blog post may seem like an oxymoron but as someone who lives in the Pacific Northwest, I can assure you that there is such as thing as cloudy sunshine. In fact, rain while its sunny is a common occurrence here.

As mentioned previously, I’ve always liked following fashion and usually make time to go through the photos of new collections of my favorite designers and discuss award show fashion choices with my cousin. I’ve never been into it enough to really pay attention to the Pantone color of the year. But in a very “Devil Wears Prada”-esque moment, I did realize that even though I don’t necessarily know what the color of the year is, that color does become the “hot color” and influences so much of what’s available to us as consumers. So I did look up the color for 2021 and it’s actually two colors, Ultimate Gray and Illuminating (bright yellow). “PANTONE 17-5104 Ultimate Gray + PANTONE 13-0647 Illuminating, two independent colors that highlight how different elements come together to support one another, best express the mood for Pantone Color of the Year 2021. Practical and rock solid but at the same time warming and optimistic, the union of PANTONE 17-5104 Ultimate Gray + PANTONE 13-0647 Illuminating is one of strength and positivity. It is a story of color that encapsulates deeper feelings of thoughtfulness with the promise of something sunny and friendly.” (https://www.pantone.com/color-of-the-year-2021)

This does go a long way to explaining the neutral/neon combos I’ve been seeing a lot of lately (and loving!!). Since I’m a huge fan of this color mix, I’d thought I do another installment of explaining the science behind things I like for the Pantone Color of 2021. This post will be slightly different in that I didn’t want to dig into color theory or the science behind how we perceive color, though both are fascinating. Instead, I found science that contained both colors to explore.

So first for Ultimate Gray – according to Pantone it is “emblematic of solid and dependable elements which are everlasting and provide a firm foundation. The colors of pebbles on the beach and natural elements whose weathered appearance highlights the ability to stand the test of time, Ultimate Gray quietly assures, encouraging feelings of composure, steadiness and resilience.” So of course the natural place to start is with rocks, or more specifically gems. While the color’s definition references pebbles on the beach, gray can be found in a wide range of rocks and gems from granite, to diamonds to nephrite. I came across this paper from 2017 that looks at color expression in nephrite (https://pubmed.ncbi.nlm.nih.gov/30160389/). Nephrite is also one of two mineral species that are called “Jade”. Now close your eyes and imagine a jade stone. What do you see? If you’re like most people, you would see anything from a deep, vibrant green to a pale, wispy green. But that wouldn’t quite fit with our Pantone Colors of the Year for 2021. As with many other stones, nephrite has a variety of colors it can be found in and one of those is a grayish-purple. It’s really a beautiful and fascinating color spectrum to the stone.

In the research paper, Chinese scientists used a variety of techniques to characterize the color of gray-purple nephrite and to determine what made the purple color in stone. What I found really compelling about this research was how they went about finding the origins of the purple color. They used a mass spectroscopy method to identify elements would could influence the color of the stone beyond the base color of gray. Mass spectroscopy is a method used to determine the chemical composition of a specimen. In this case, a slice of the nephrite was ionized causing some of the specimen’s molecules to become charged (some also become fragmented). These charged particles are separated based on their mass-to-charge ratio (a measure of relative size) and detected by a mechanism capable of detecting charged particles. The read-out is a spectrum that shows signals as peaks of different sizes and shapes. These peaks correspond to known masses (i.e. of an entire molecule) or a characteristic fragmentation pattern. So, in a nutshell, scientists charged up a sample, accelerated those charged particles to a detector and then examined the characteristic pattern of peaks to see if they matched any known molecules. What they found is the that regions that were more purple contained more manganese. Additional testing showed more evidence to support manganese as the origin for the purple color in nephrite. Looking at manganese compounds, this makes some sense. Manganese itself is a silver-gray metal is not found as a free element in nature. It commonly bonds with iron, which can be used as a black paint or dye (which can be seen in ancient cave paintings). It is also found as potassium permanganate, which is a purple salt. Manganese can also be found in various oxides in nature, which produce colorful pigments themselves. This very versatile element in nephrite leads to a beautiful purple hue.

So that was a fairly deep rabbit hole I went down with the nephrite and honestly, I could have kept researching manganese. It’s fascinating. But there are other interesting occurrences of gray in the natural world. One of the most obvious, that I would be remiss not to mention, is the gray matter that makes up our brains. While the inclusion of gray in the Pantone color selection was meant to be positive and uplifting, wading through publications on gray matter research is not. The majority of the research is around gray matter defects or other conditions that impact brain function. While it’s very understandable that scientists would want to research conditions, try and find cures, yada, yada, yada, that doesn’t lend itself well to the theme of this post. And if any of you know me, you know I love a good theme. After much diligent searching (read: scrolling through PubMed), I did find an interesting and uplifting piece of research on gray matter.

First – some orienting to gray matter for those of us who haven’t had any anatomy since dissecting a fetal pig freshman year of college. Gray matter can be found in the brain, brain stem and spinal cord. It is comprised of neuronal cell bodies, dendrites and unmyelinated axons, glial cells, synapses and capillaries. It is a gray-yellow or gray-pink color due to the presence of cell bodies and capillaries and the absence of myelinated axons (which are white and which give white matter is moniker). In the brain, the gray matter regions are involved in muscle control, sensory perception, decision making and self-control.

In 2019, an article was published in Frontiers in Human Neuroscience looked at musical improvisation and gray matter volume. (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6538978/pdf/fnhum-13-00169.pdf). Students from two music schools were given a musical prompt and asked to play along with the prompt and then to improvise in the most creative way they could. The participants then underwent brain imaging by T1 MRI. Recordings of the improvisation were scored by 3 jazz improv experts. Interestingly, creativity ratings from the experts were negatively correlated with decreased gray matter volume in the bilateral hippocampus (learning and memory formation) and right inferior temporal gyrus (categorization of meaningful stimuli) and rolandic operculum (interoception or awareness of one’s own heartbeat). In conclusion, they found that individual differences in musical creativity are associated with differences in brain structure in regions involved in memory formation and categorical representation. Additionally, brain areas that are involved in sensory integration are associated with the duration of improvisation training. The scientist in me is now curious about if these differences are innate or can they be developed and changed throughout time. I thought this was a lovely image, thinking that musical creativity is driven by biological processes as I’ve always been in awe of the biological machine that is the human body and its complex, nuanced, operation.

So we’ve looked at “Ultimate Gray” in science a little bit. What about “Illuminating” or yellow. I will preface this section by saying that I went with the yellow color more than the neon aspect. I may do another post about neon in general because it’s fascinating. Let’s see what Pantone has to say about Illuminating: “PANTONE 13-0647 Illuminating is a bright and cheerful yellow sparkling with vivacity, a warming yellow shade imbued with solar power”. Now it would be tempting to think that I would link the color to solar research and that was an initial thought. But as I was doing the research, I came across two research articles that were fascinating both because they had to do with yellow but also because they had to do with textiles.

The first was an article published in 2007 looking at dyes in pre-Columbian textiles. (https://pubs.acs.org/doi/10.1021/ac061618f) Unfortunately, the article was behind a pay wall and this blog is just a hobby so I’m not shelling out cold, hard cash to read a whole article (sorry folx). However, the abstract was pretty informative. The textiles were discovered mostly in Northern Peru and data from 1050-1200 AD. The dyes were extracted from the fabric and run through high-performance liquid chromatography (HPLC) and mass spectrometric detection. Now we covered mass spectrometry earlier in the article so I hope you all remember that methodology. HPLC is a method that is used to separate, identify and quantify components of a mixture (in this case the yellow dye). In HPLC, liquid solvent and sample are pumped through a column filled with adsorbent material. The various components of the sample interact differently with the adsorbent material and thus come off the column at different rates. Various detection methods are used to detect the different components of the sample. The results are visualized by different peaks on a chromatograph. When the scientists used these two techniques on the yellow dye found in the textiles, they found two major types of dye. One dye was derived from the Flaveria haumanii plant, or something very close to that. The second major yellow dye contained compounds that did not have a known plant source. The sample also contained two other types of yellow dye that could not be identified due to low sample volume. Interestingly, the authors state that most yellow dyes are synthesized in plants as glycosides, which the research team found, and those are incorporated into textile fibers during dying as mostly intact molecules. As with the purple/gray jade, it is fascinating to me to learn where color comes from and how people use it. Apparently, yellow was quite a popular color back in the pre-Columbian era. Perhaps it was even color of the year in 1200 AD. Who knows, they say fashion always repeats itself.

Of course its super cool, at least to this science geek, to hear about how color is created in materials. What about how color is destroyed? An article published in 2017 details yellow dye-decolorizing bacteria found in Indonesia (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5300016/pdf/tlsr-28-1-69.pdf). Azo dyes are a major water pollutant in Indonesia. The dyes are brightly colored and water soluble and used widely in textile finishing. Since about 10-15% of the dye is are lost to effluent during the dyeing process, that leads to high levels in the water. The dye Metanil Yellow has been shown to induce allergic dermatitis upon skin contact and there is a link to tumor-producing properties of the dye. To help reduce the impact of this dye out in nature, scientists looked in soil from around textile producing sites and cultured that soil searching for bacteria that could perform bioremediation on the dye. What they found was bacteria that could de-colorize the dye, leading to lesser ecological impact since the dye is being broken down in the constituent parts. In fact, some of the species of bacteria in the soil samples were able to de-colorize the yellow dye in 3-6 days, depending on the concentration of the dye solution added. What is especially neat about these particular bacteria is that they also have the ability to neutralize molybdenum in the soil as well. Molybdenum is an element used in a wide variety of industries such as lubricants, electronics and pigments. There is some research to indicate that molybdenum is toxic to spermatogenesis in animals, and the fumes and dust of the element can cause severe symptoms in humans. So these super bacteria not only break down a toxic yellow dye, they also remediate other industrial pollution. I have to admit that I’m fan-girling a little bit over here. One of the reasons I did my undergraduate degree in biotechnology was an experiment I did in high school. We engineered E. coli to be resistant to a specific antibiotic, and then promptly destroyed them of course. I was completely enraptured by the flexibility and adaptability of bacteria. To this day, it doesn’t cease to amaze me what these little powerhouses of the microbiological world can do.

So we’ve found yellow being created and yellow being destroyed. Where does that leave us. I think I’ll leave the discussion on yellow with one final piece of not-quite scientific fact. There is supposition that the yellow period in Van Gogh’s life and the subsequently unusual nature of the sky in his “Starry Night” is because of digitalis intoxication. Digitalis is an extract of foxglove plants and was used, among other things, to treat epilepsy. Today, components of digitalis, such as digoxin, are used as standard medications. The theory that Van Gogh was suffering from digitalis intoxication comes from him having twice painted his physician holding the foxglove plant. (https://jamanetwork.com/journals/jama/article-abstract/373788) The target enzyme for digitalis is abundant in the cone cells of the eye, which are responsible for color perception. One side-effect of people on digitalis-derived medications is haziness of the eye and an overall yellow tinge to their sight. (https://www.theguardian.com/science/blog/2017/aug/10/it-was-all-yellow-did-digitalis-affect-the-way-van-gogh-saw-the-world) Of course, it’s impossible to retrospectively diagnose someone so there’s no way to know for sure why Van Gogh used the color yellow so much. Perhaps he was just very ahead of his time in anticipating it’s prominence as a color of the year.

Hope you enjoyed this installation of The Science Behind Things I Love (I have to come up with a better name). Until next time!

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