Color Harmony Increases the Capacity of Visual Short Term Memory

Do color relations influence the ease and pleasure with which colors combine in mind? For almost two centuries, the hypothesis of color harmony has been supported by systematic explorations of subjective color pleasure (e.g., Chevreul, 1839/1991). Here, we replicate subjective pleasure while introducing methods for examining the consequences of color harmony for an objective measure of mind - the ease of holding colors in visual short term memory (VSTM). We used the standard change detection method to measure capacity for holding colors in VSTM. Patterns of 9 to 15 contiguous color squares were presented to observers to hold in memory for 1 sec and compare against a same or different (one changed color square) test pattern. Pattern colors were randomly selected from palettes of 4 colors; harmony was defined as same or similar hue category within palette. Harmonious color palettes were much more pleasant than the disharmonious palettes, as confirmed by observer ratings. In two experiments with differing sets of colors, VSTM accuracy was reliably higher for harmonious patterns than for disharmonious patterns. Estimated capacities, in terms of number of color squares, were reliably higher with harmonious palettes. Furthermore, as pattern size increased (increasing the load on memory), the advantage for harmony increased. The results indicate that color harmony increases both subjective pleasure and objective capacity for holding colors in mind. Controls. Actual color changes were the same between harmony conditions. The harmony advantage cannot be explained by luminance heterogeneity because harmonious and disharmonious were similar on that in Experiment 1. Number of color categories per palette was equated in Experiment 2. In a separate experiment, harmonious contexts interfered somewhat with discriminating the critical color changes, consistent with the conclusion that harmony influences memory capacity rather than color discrimination