Methodological consideration in color research

A Historically Based Review of Empirical Work on Color and Psychological Functioning: Content, Methods, and Recommendations for Future Research

Empirical work on color and psychological functioning has a long history, dating back to the 19th century. This early research focused on five different areas: Arousal, physical strength, preference, time perception, and attention. In the present paper, I overview the relations observed in this early research, and detail methodological weaknesses therein. I then trace subsequent 20th and 21st century developments in these research areas, in terms of both content and methods. Finally, I extend the review to cover the full breadth of research in this domain of inquiry, and provide guidelines for interpreting existing work and conducting future work. Thus, this historically based review tells us much about research on color and psychological functioning, including where it started, where it has been, where it is, and where it can go.

Quantification of dichromatism: a characteristic of color in transparent materials

The color of a material, such as solution of a dye, can change by changing parameters like pH, temperature, illumination direction, and illumination type. Dichromatism -- a color change due to the difference in thickness of the material -- has long been known as a property of only a few materials. Here we show that dichromatism is a common property of many substances and materials, and we introduce a method for its quantification. We defined dichromaticity index (DI) as the difference in hue angle (Delta h(ab)) between the color of the sample at the dilution, where the chroma is maximal, and the color of four times more diluted (or thinner) and four times more concentrated (or thicker) sample. The two hue angle differences are called dichromaticity index toward lighter (DI(L)) and dichromaticity index toward darker (DI(D)), respectively. High dichromaticity was found for materials that were previously known as dichromatic (pumpkin oil, bromophenol).

Physicochemical and physiological basis of dichromatic colour

Out of three perceptual characteristics of the colour of any substance, the hue depends mostly on the spectral properties of a substance, while the brightness and saturation depend also on the concentration of a substance and its thickness. Here, we report that evident change of the hue of the colour (i.e., from green to red) is due to a change in concentration or the thickness of a layer in some exceptional substances such as pumpkin seed oil or an aqueous solution of bromophenol blue. In some regions of Central Europe, salad dressing is made preferably with the pumpkin seed oil, which has a strong characteristic nut-like taste and remarkable properties of the colour: it appears red in a bottle, but green when served as a salad dressing. The colour of the pumpkin seed oil was previously described as brownish yellow, dark green, dark green to red ochre or dark reddish brown to light yellow green. We elucidated the physicochemical and physiological basis of such dichromatism by Beer-Lambert law and by the characteristics of human colour perception. Our concept was corroborated by the outcome of calculations of colour from spectral properties using colour matching functions. We found that dichromatism is observed if the absorption spectrum of any substance has at least two local minima: one wide but shallow and one narrow but deep local minimum.

Color or brightness effects on grip strength?

Research into the effects of color on grip strength has produced inconsistent results, but studies show methodological problems, for example, the non-standardised reporting of stimulus colours, differing intertrial rests, and the neglect of warm-up effects. The present study was designed to replicate the 1989 work by Hasson, et al. and also to examine potential brightness effects of stimuli on grip strength. Analysis indicated brightness effects might confound potential to produce Type I errors.

Thoughts on perceptual influences of colored paper

Much of the material one reads is in black and white. It is proposed that the color of paper may influence perception and performance on pen-and-paper tasks.