Color Me Excited! Munsell visits MSU Campus Archaeology Program

During the last week of our undergraduate archaeological field school, Art Schmehling and Laura Weeks from Munsell came out to visit our excavation, show us a few of their products, and see how we typically use their soil color book. The products they brought and taught us about included their new Munsell CAPSURE Color Matching Tool!

They also provided us with the Farnsworth Color Vision Test so we are able to evaluate the extent that our color vision can tell the difference between specific colors and hue variations within a given color. This test indicates our color acuity across the entire spectrum of visible color, which is an essential skill for archaeologists.

Archaeologists typically use the Munsell Soil Color Book to evaluate soil strata (layers of soil) during our excavations. It allows us to learn how the archaeological record was formed, a process in which layers of soil and cultural material are laid down on top of one another through time. Soil color changes and the presence of cultural material also allows archaeologists to look at and tell the difference between natural and cultural deposition episodes and/or activities. If you are interested in how archaeologists ‘read’ soil stratigraphy, take a look at a previous blog post: https://campusarch.msu.edu/?p=334.

We were excited to try out the new Munsell CAPSURE Color Matching Tool in comparison with our traditional way of using the soil color book! Several Campus Archaeology staff and field school students tried out the device. To get the most accurate reading, the soil must be clean scraped and made as smooth as possible. You place the device flat against the soil and press a button on the side to capture the color. The device provides a Munsell color (i.e. 10YR3/4), and it also allows you to view colors that have been categorized as similar.

When we tested the same soil sample using both methods (book and digital device), we found that we identified colors the same or similar to the digital device’s readings. While this didn’t happen every time, we found that inclusions greatly impacted the color that the digital device selected. We also challenged the CAP staff to categorize the same soil layer using a paper Munsell book in order to see if we categorized colors in a similar fashion. While we mostly agreed, there were some soil layers that we identified as slightly different. Overall, we believe the device would be useful on a large scale excavation that could benefit from consistency, as individuals perceive colors in different ways and would assist in increasing work flow.

To test how differently we identify colors, we used the color vision test provided to us by Munsell. Two professors, three graduate students, and one undergraduate intern completed the test. Our results ranged from ‘average discrimination’ to ‘superior discrimination.’ The definitions of the discriminations from the test are below:

Superior Discrimination
About 16% of the population (exclusive of color defectives) has been found to make 0 to 4 transpositions on first test, or total error score of zero to 16. This is the range of superior competence for color discrimination.

Average Discrimination
About 68% of the population (exclusive of color defectives) make a total error score between 20 and 100 on first tests. This is the range of normal competence for color discrimination.

Low Discrimination
About 16% of the population (exclusive of color defectives) has been found to make total error scores of more than 100. The first retest may show improvement, but further retests do not materially affect the score. Repeated retests reveal no region of large maximum or minimum sensitivity as is found in color defective patterns.

It was interesting to see how we all view color changes and hue variations. One thing to note is that we all picked out one of the color samples as not fitting in well within the color spectrum; we all agreed it appeared brighter than the surrounding colors it was designated to sit between.

We appreciate Art and Laura taking the time to come out to the field school site, as well as providing us with the vision test! We are looking forward to taking a trip to visit their facility this fall to learn more about Munsell and how they make the colors.

Author: Autumn Painter