Color discrimination was estimated using the Cambridge Colour Test (CCT) in 160 normal trichromats of four life decades, 20-59 years of age. For each age cohort, medians and tolerance limits of the CCT parameters are tabulated. Compared across the age cohorts (Kruskal-Wallis test), the Trivector test showed increases in the three vectors, Protan, Deutan, and Tritan, with advancing age; the Ellipses test revealed significant elongation of the major axes of all three ellipses but no changes in either the axis ratio or the angle of the ellipse major axis. Multiple comparisons (Mann-Whitney test) between the cohorts of four age decades (20+,…,50+) revealed initial benign deterioration of color discrimination in the 40+ decade, as an incremental loss of discrimination along the Deutan axis (Trivector test), and in the 50+ decade, as an elongation of the major axes of all three ellipses (Ellipses test).

Color vision impairment emerges at early stages of diabetes mellitus type 2 (DM2) and may precede diabetic retinopathy or the appearance of vascular alterations in the retina. The aim of the present study was to compare the evaluation of the color vision with two different tests - the Lanthony desaturated D-15d test (a traditional color arrangement test), and the Cambridge Colour Test (CCT) (a computerized color discrimination test) - in patients diagnosed with DM2 without clinical signs of diabetic retinopathy (DR), and in sex- and age-matched control groups. Both color tests revealed statistically significant differences between the controls and the worst eyes of the DM2 patients. In addition, the degree of color vision impairment diagnosed by both tests correlated with the disease duration. The D-15d outcomes indicated solely tritan losses. In comparison, CCT outcomes revealed diffuse losses in color discrimination: 13.3% for best eyes and 29% for worst eyes. In addition, elevation of tritan thresholds in the DM2 patients, as detected by the Trivector subtest of the CCT, was found to correlate with the level of glycated hemoglobin. Outcomes of both tests confirm that subclinical losses of color vision are present in DM2 patients at an early stage of the disease, prior to signs of retinopathy. Considering the advantages of the CCT test compared to the D-15d test, further studies should attempt to verify and/or improve the efficiency of the CCT test.

The present study, an extension of Paramei [J. Opt. Soc. Am. A, 29, A290, 2012], provides normative data on chromatic discrimination, using the Cambridge Colour Test, for normal trichromats aged 10-88 years. Findings are in accord with a two-phase variation across the life span: chromatic sensitivity improves in adolescence, reaches a maximum around 30 years, and then undergoes a gradual decrease. Indicative parameters are Protan (P), Deutan (D), and Tritan (T) vector lengths and major axes and axis ratios of Ellipses. Trivector data are modeled as non-monotonic combinations of power functions, with goodness-of-fits R(P)2=0.23, R(D)2=0.23, and R(T)2=0.45. For advancing age, sensitivity decline in all chromatic systems was confirmed, though with a marked acceleration after 60 years (reflected by the power function exponent >1) and more pronounced for the tritan system.

The universal inventory of basic color terms (BCTs) consists of 11 terms, including a single blue term. Russian has two terms for blue, sinij (dark blue) and goluboj (light blue). The proposed status of goluboj as the 12th basic term challenges theory stating the upper limit of BCTs. This article reviews a body of research on the Russian blues and draws on arguments from lexical-semantic analysis and linguistic and psycholinguistic studies. It is argued that goluboj, being symbolically charged, emerged in Russian as culturally basic. Counterparts of the Russian blues in other languages are considered. Within a context beyond Russian, the potential refinement of the blue area is suggested to follow perceptual-cognitive universals. This is reinforced by language and culturally specific semiotics. By drawing attention to a distinction between denotative and designative meaning, the issue of the Russian blues calls into question the proper definition of a basic color term.

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Gender differences in colour naming were explored using a web-based experiment in English. Each participant named 20 colours selected from 600Munsell samples, presented one at a time against a neutral background.Colour names and typing onset response times were registered. For the eleven basic colour terms, elicitation frequency was comparable for both genders. Females demonstrated though more elaborated colour vocabulary, with more descriptors in general and more non-basic monolexemic terms; they also named colours faster than males. The two genders differ in the repertoire of frequent colour terms: a Bayesian synthetic observer revealed that women segment colour space linguistically more densely in the "warm" area whereas men do so in the 'cool' area. Current "nurture" and "nature" explanations of why females excel in colour naming behaviour are considered.

Russian color naming was explored in a web-based experiment. The purpose was 3-fold: to examine (1) CIELAB coordinates of centroids for 12 Russian basic color terms (BCTs), including 2 Russian terms for "blue", sinij "dark blue", and goluboj "light blue", and compare these with coordinates for the 11 English BCTs obtained in earlier studies; (2) frequent nonBCTs; and (3) gender differences in color naming. Native Russian speakers participated in the experiment using an unconstrained colornaming method. Each participant named 20 colors, selected from 600 colors densely sampling the Munsell Color Solid. Color names and response times of typing onset were registered. Several deviations between centroids of the Russian and English BCTs were found. The 2 "Russian blues", as expected, divided the BLUE area along the lightness dimension; their centroids deviated from a centroid of English blue. Further minor departures were found between centroids of Russian and English counterparts of "brown" and "red". The Russian color inventory confirmed the linguistic refinement of the PURPLE area, with high frequencies of nonBCTs. In addition, Russian speakers revealed elaborated naming strategies and use of a rich inventory of nonBCTs. Elicitation frequencies of the 12 BCTs were comparable for both genders; however, linguistic segmentation of color space, employing a synthetic observer, revealed gender differences in naming colors, with more refined naming of the "warm" colors from females. We conclude that, along with universal perceptual factors, that govern categorical partition of color space, Russian speakers' color naming reflects language-specific factors, supporting the weak relativity hypothesis. K E Y W O R D Scentroids, CIELAB, color naming, color space, gender differences, linguistic segmentation, Russian, webbased experiment | I NT ROD UCTI ONAccording to its color, a visual stimulus is assigned to a certain color category. Identified by a linguistic label (in adult humans), language-specific concepts enable attention to be drawn to certain perceptual attributes of reality. Color names, like other groups of semantically related words, are systems in which one word's position influences the positions of all others.