Several color theories flourished during the 19th century, marked by experiments on the distinction between color-light and color-matter. This study aims to compare the color plates designed to illustrate three of these color theories, namely M.E. Chevreul's chromatic circle (1861), O. Rood's frontispiece (1879), and C. Henry's color circle (1889). These printed plates played a key role in disseminating their respective theory to a broad public. However, the question of their design remains relatively unknown. A non-invasive multimodal approach was applied, combining visible and near-infrared reflectance imaging, x-ray fluorescence, Raman, and mid-infrared Fourier transform spectroscopies to characterize the materials and printing techniques used to depict the different color theories. It provided new information on the visual appearance of these plates, as well as a deeper understanding of the design of each unique color space and how it relates to their theoretical conceptualization. Analysis of the materials revealed a number of pigments common to all three color spaces, such as red lake pigment, chromate lead, Prussian blue, minium, and vermilion. The use of these pigments and their positioning in the color space illustrate that the choices of the three scientists are guided by the theory they wish to illustrate. Their objectives are not the same: M.E. Chevreul proposed a chromatic circle to illustrate his contrast of simultaneous colors, whereas O. Rood differentiated between a mixture of colored light and a mixture of colored matter. Finally, C. Henry appears as their heir, representing both color-light and color-matter on the same circle while following his esthetic rules of color placement.
{"title":"Unveiling the Materiality of 19th Century's Color Spaces","authors":"Aurore Malmert, Oulfa Belhadj, Christine Andraud, Emeline Pouyet","doi":"10.1002/col.22982","DOIUrl":"https://doi.org/10.1002/col.22982","url":null,"abstract":"<p>Several color theories flourished during the 19th century, marked by experiments on the distinction between color-light and color-matter. This study aims to compare the color plates designed to illustrate three of these color theories, namely M.E. Chevreul's chromatic circle (1861), O. Rood's frontispiece (1879), and C. Henry's color circle (1889). These printed plates played a key role in disseminating their respective theory to a broad public. However, the question of their design remains relatively unknown. A non-invasive multimodal approach was applied, combining visible and near-infrared reflectance imaging, x-ray fluorescence, Raman, and mid-infrared Fourier transform spectroscopies to characterize the materials and printing techniques used to depict the different color theories. It provided new information on the visual appearance of these plates, as well as a deeper understanding of the design of each unique color space and how it relates to their theoretical conceptualization. Analysis of the materials revealed a number of pigments common to all three color spaces, such as red lake pigment, chromate lead, Prussian blue, minium, and vermilion. The use of these pigments and their positioning in the color space illustrate that the choices of the three scientists are guided by the theory they wish to illustrate. Their objectives are not the same: M.E. Chevreul proposed a chromatic circle to illustrate his contrast of simultaneous colors, whereas O. Rood differentiated between a mixture of colored light and a mixture of colored matter. Finally, C. Henry appears as their heir, representing both color-light and color-matter on the same circle while following his esthetic rules of color placement.</p>","PeriodicalId":10459,"journal":{"name":"Color Research and Application","volume":"50 5","pages":"487-498"},"PeriodicalIF":1.4,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/col.22982","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144915091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Omnia Saleh, Sascha Hein, Stephen Westland, Mayumi Maesako, Akimasa Tsujimoto, Konstantinos Michalakis
This study aimed to classify the natural tooth color spaces of various ethnic groups and assess the coverage error (CE) of the Vita 3D-Master shade guide. A sample of 490 volunteers from five ethnic backgrounds participated, with inclusion criteria set for adults aged 20– to 45 with healthy, correctly aligned natural teeth free of restorations. Teeth showing caries, restorations, or substantial staining were excluded. Tooth color was measured through a standardized photographic method, employing a gray reference card and cross-polarized filters. Color differences were computed using the CIEDE2000 formula, and CE was determined. Examiner reliability was verified, and data were analyzed in R software, with significance set at p < 0.05. The results indicated significant disparities in tooth color parameters among ethnic groups. Lightness levels varied significantly, with African teeth presenting the highest values and Caucasians the lowest. While redness and yellowness values overlapped among some groups, African, Middle Eastern, and South Asian teeth showed higher redness, whereas East Asian and South Asian teeth were more yellowish. The mean CE of the Vita 3D-Master shade guide was 5.1 ∆E