Monday, March 21, 2011

Quantifying Color for Crawling Critters

I wanted my next post on this blog to be a  comparative morphology of 3 individuals of Stenotrema hirsutum I have from 3 separate locations, but thinking about this subject brought me to the idea of color.

In my day job as a graphic designer I deal with color quite a bit. I've been fed color theories, color cultural meanings, etc. On top of that, when I used to be a  professional photographer I became well versed in the qualities of light and how they relate to color. So color is no stranger in my world-- one of a visual arts professional.

However, the visual is pretty much what I'm most interested in, not only in my career, but in my hobbies. For instance, I am a birder as one of my main hobbies. And, although I'm well versed enough to know their sounds and able to identify solely using that sense, I never care for only hearing a bird. I always want to see it. Snails also are a visual affair for me. While many people probably have never taken the time to appreciate the very subtle beauty of land snails (sure, maybe some other shells like the fancy Cones I only learned of at the MAM meeting), I find quite a bit of visual intrigue in the the subtle gradation of shell features. Plus I find the live animals just plain cute.

Let's face it, the world, including the malacological world, revolves around the visual uptake of information. Proof is that snails aren't usually described base on their textures (at least not tactually, although texture is described visually, but I've never heard a description of the feeling one gets when touching) , their smells (well, maybe Oxychilius alliarius-- aka the Garlic Snail), or their sounds (unless you went to the MAM meeting the other day).

Before I hit too much of a tangent, the reason for this post is to question some of the whys, why-nots, and methods of thinking about color as it pertains to land snails. There are a few things that strike me about the accounts/data of snails I've been reading in Pilsbry and Burch:

  1. The adjectives used to describe are not exact. Maybe their not as bad as walking into a paint store and seeing nonsense names like 'december mist' and 'autumn night,' but their still not very scientifically precise. Words are used like 'cinnamon-buff' and, one I still have no idea what it is, 'horn' are used. Not very quantifiable or reproducible in my mind. 
  2. Body color descriptions aren't often given. I think it would help to have body colors included to help speciate a live animal, but often this information is non-existant. 
  3. With no exacting data on colors one can't make any postulations based on color. For instance, maybe a link between diet and body color could be made (think Flamingoes and the shrimp they eat). Or habitat and color... or whatever. I'm obviously not a scientist or versed enough in land snails to know if this might be scientifically viable, but I still find this idea stimulating. In birds there is a theory that comes to mind to show, though, that this is likely viable in some way. Unfortunately I don't have the book here in New York with me to quote directly, but, if I remember correctly, the theory says that area that are more wetter and colder have darker, larger individuals of a species while dryer, warmer have smaller, lighter colored birds of a species. And of course there is gradation of the species all in between. (I may have larger and smaller backwards, I'll have to check when I get back to Pennsylvania).
So I feel there is value to a quantifiable, reproducible method for describing color in land snails. Which leads to the next question: What's the best way to describe this color.

Well, it's certainly not 'blue,' 'dark blue,' or 'summer at midnight.' It's best to turn to established color models for the nomenclature.

First, let's buzz through the amateur hour colors of a graphic designer's day. CMYK- no, it's just reflected light, made for what ink can produce. RGB- no it's an additive color model made for what's reproducible on a monitor... no help there.

The color models that really will be helpful and that most graphic designers live in the hazy periphery of are LAB and the Munsell color systems.

Munsell predates the LAB and I believe LAB is just a child of Munsell. I'll leave a wikipedia search for you if you want to find out more. But the main point here is that both are based on the colors that are seeable by the human eye. This would make these ideal methods for describing color, seeing as we'd be hard pressed to find a color not describable by these models, at least, not one we're going to be trying to describe. Side tangent- maybe there are some ultra colors we'd want to describe. Look at crows. To our natural eyes they are just big black birds. But crows actually have an incredible ultraviolet pattern which, apprently, must be seeable by other crows.

Let's go into a few methods I came up that might be viable for your average, everyday snailer to describe color, including their pros and cons.

Method #1: Description By Comparison

The first method that could be useful is comparing a standard color set to the creature. In the graphic design world we use the Pantone color swatches often to make sure inks match up in the printed piece the colors we intended when designing. It's become a standard in the industry. Could we use that same Pantone system for this purpose? Maybe. But limitations include that these swatches only can contain what can be printed (remember, our color models go beyond what ink can do), human error, and the fact that, due to the qualities of light, we would need to make such a comparison in color corrected light so as not to skew the results of the viewer.

Method #2: A Colorimeter

This might be the best method I can think of. While I have experience with a colorimeter for photographic purposes (when I did architectural photography primarily) I have no experience with a full on laboratory colorimeter so I can't speak of its results, how it works, etc. Even Pantone, as mentioned above, has its own colorimeter that, for about $600, you can put up to something and get a color readout. The only potential pitfall (besides price) is that it might not be able to sample extremely small snails. And I have no idea if it reads out colors that are visible by human eye and not reproducible by ink.

Method #3: Photography

Photography is pretty accessible, especially in the digital age. I figure you'd need to take every photo with a color chart and completely correct color balance for consistency. Lighting would also need to be standardized and you would need to light for complete and utter flatness of lighting. Sampling the color from a slight highlight or slight shadow could skew results. Maybe color averages would have to become involved. Then a standardized method would be needed to take those values. Photoshop is pervasive and provides a handy method for this and actually contains pretty much both color models (Munsell is pretty  much the HSB-hue saturation brightness- values). We're still up at a wall against the colors that are reproducible, though.

A couple other points I wanted to make, but I'm tired and need to go to sleep, is some standardization. For instance, for semi-transparent shells do you take the color of the empty shell or with the animal in the shell. And pitfalls include trying to quantify the color of shells that have been sitting for some time and changed colors due to environmental factors.

Well, I've prattled on a bit about this subject and have no answers. I've yet to even do so much as a google search on the subject but liked the idea of thinking it out myself. Further questions remain as to proven/useful methods and viable use of the data to both scientists and enthusiasts such as myself. Really, as I started to think out the table of characteristics of my 3 Stenotrema hirsutum I became hung up on the thought of how to best describe the shell and body colors in a scientifically accurate and reproducible manner. Of course, I'll probably still describe my S. hirsutum in the same manner as Pilsbry with colors like 'cinnamon-buff' and 'clay.' Stay tuned for that article.