Background
We have recently been studying the imagery of irritable bowel syndrome and shown that patients who have an image of their condition respond better to hypnotherapy than those who don't [
1]. Furthermore, the response was even better if the image was in color. This has led us to speculate that how patients relate their illness or mood to color might be an area worthy of further investigation.
Colors are frequently used to describe emotions such as 'green with envy', 'red with rage' and being 'in the blues' when depressed. Although there is a large, often anecdotal, literature on color preferences [
2‐
4] as well as the relationship of color to mood[
5,
6] and emotion[
2,
7,
8] there has been relatively little systematic research on the subject [
9‐
13]. Furthermore we could not find a single validated questionnaire specifically designed to rapidly identify color preferences in any previous investigations. When instruments have been developed such as the Color Pyramid test,[
14] the Rorschach Inkblot test,[
15] the Lüscher Color test,[
16] the Lowenfeld Mosaic test[
17] and the Stroop test[
18] they have been designed more to interpret, for instance personality or cognitive processing, rather than allowing a subject to simply select a single color to represent their mood or disease.
It was therefore felt that it would be worth developing a color questionnaire which could present a reasonably wide range of colors in the form of a palette, similar to those used in paint charts, which would suit our purpose but may also have utility in a wide range of other areas of investigation and diagnosis. Validation was undertaken in normal individuals with respect to their 'drawn to', 'favourite' and 'mood' color choice with the purpose of identifying a 'normal range' of responses. In addition, anxious and depressed subjects were also studied as it was anticipated that their color choice might be distorted by their mood and this would aid the validation process by assessing discrimination between mood states. Furthermore, it was considered likely that different shades of the same color, for instance pale green and dark green, could have completely different connotations for the individual. Consequently, the positive and negative attributions of the colors in the questionnaire were also assessed as part of the validation process.
Discussion
Colors are all about us and the sheer variety of shades used in, for instance interior decorations, are an indication of the wide range of preferences that exist. This study describes a novel way of documenting the color preferences of individuals which is extremely easy to use.
In addition to studying healthy volunteers it was felt necessary to also include a group of individuals in whom color choice might be distorted. It was hypothesised that people with depression would be most likely to show a definite effect between color and mood as even in every day life dark colors are often regarded as depressing. Individuals with anxiety were also studied to test the discriminant power of using color to define mood. In other words, if anxious individuals selected different colors it would suggest that color choice is identifying a specific state of mind rather than just reflecting a more general change in mood.
There was remarkably little difference in choice of 'drawn to' or 'favourite' color between individuals irrespective of whether they were healthy, anxious or depressed. 'Yellow 14' was the most popular 'drawn to' color and with respect to 'favourite' color, 'Blue 28' was the most popular color choice of healthy and anxious individuals with 'Blue 27' being the first choice of the depressed subjects closely followed by 'Blue 28'. These results are in accord with the findings of previous investigators who similarly have found that blue was the favourite color choice of adults[
2‐
4,
8,
21‐
23]. It is noteworthy that only two individuals chose a grey shade or white as their favourite color.
The results for mood color were in stark contrast to those obtained for 'drawn to' and 'favourite' color. Only 39% of healthy volunteers associated a color with their mood compared to 70% of anxious and 79% of depressed which suggests that individuals with affective disorders are more likely to equate their mood with a color. 'Grey 35', 'Grey 36' and 'Grey 37' dominated the top four places of the anxious and depressed groups, a theme broken only by 7% of anxious individuals who chose 'Red 3' to describe their mood likening it to anger, stress and frustration. Comments about the choice of grey included relating it to a dark state of mind, a colorless and monotonous life, gloom, misery or a disinterest in life rather than the color grey being chosen because of its colloquial associations with a low mood. These descriptions are in keeping with the observations of others suggesting that depressed patients viewed life as "monochromatic"[
24] or having "lost its color"[
25]. It has even been suggested that depressed people might exhibit color impairment and that it might be a state or trait marker of mood disorders[
26]. The results for the anxious and depressed individuals differed considerably to those in healthy volunteers who associated 'Yellow 14' and the yellow colors in general as the color most representative of their mood. Another noteworthy observation was that anxious and depressed individuals were significantly less likely to choose 'Yellow 14' to describe their mood and significantly less likely to choose colors from either the red, orange or yellow color groupings. In the literature yellow has been reported as being associated with happiness, cheerfulness and a positive emotional state[
5,
6,
27,
28]. It has been suggested that differences in color saturation and brightness are associated with different emotional feelings[
29] and it is possible that this could provide an alternative explanation for the different mood color responses that have been observed in this study. For instance, healthy individuals may relate their mood to saturated colors whereas depressed subjects choose desaturated colors. Color choice was not related to gender in the group as a whole and this is in accord with the older literature which suggests that although it may be different in children this is lost with adulthood. However, there were more women in all of the study groups which may have reflected the method of recruitment by advertisement and global e-mail, although anxiety and depression are more common in females, which is a more likely explanation for the gender imbalance. Consequently it was necessary to ensure the gender distribution of the healthy group matched that of the other two groups so that the gender distribution was approximately equal across the whole study. A more recent study has suggested there may be differences in color choice between males and females[
30] but this needs to be confirmed and does not strictly affect the validation of the instrument, which could actually be used to investigate this question in the future, especially in larger samples. The use of antidepressants in those with anxiety or depression did not appear to affect color choice. The lens of the eye tends to become more yellow with age and this could theoretically affect color choice. However there is evidence that this is compensated for, possibly by neural mechanisms,[
31] and consequently this effect was not looked for especially as the number of elderly subjects was relatively small.
It was felt that reproducibility would be an important part of the validation exercise to ensure that choice was not just a random process. Consequently a sample of subjects from both Study 1 and 2 were asked to repeat the questionnaire two weeks later. This interval was selected because it was felt that color choice should remain fairly constant over this period of time, but it was long enough for them to forget their original choice. Some interesting observations emerged when reproducibility was examined. With respect to 'drawn to', 'favourite' and 'mood' color the reproducibility, 34%, 46% and 64% respectively, might initially appear to be rather poor. However, it was noteworthy that even if an individual did not choose exactly the same color on the second occasion they often chose one closely related on the color spectrum, e.g. 'Red 3' on the first and 'Pink 21' on the second. If the data are assessed using this criterion then reproducibility increases to 59%, 78% and 76% respectively. Another critical finding in this study was that the shade of a color was a very important factor. Consequently color groupings, such as reds, greens and yellows may not be a good way of assessing color preferences. This is because it became clear from this study that a pale shade of a color may have a completely different connotation to a much darker shade. For instance, dark blue may have similar mood or emotional connotations to dark brown rather than to a pale shade of blue. These problems can be overcome by adopting the alternative methodology of classifying a color as either positive or negative. When this was undertaken reproducibility reached extremely high values of 88% and 91% respectively for positive or negative shades suggesting that this approach may be much more robust than relying on individual color choice.
When colors were assessed according to their positive and negative associations it was observed that there was a tendency for some colors, such as yellow or black, to be far more commonly rated as either positive or negative than others. Thus, it was possible to create a variety of permutations which at one extreme were restricted to just the most highly rated positive or negative colors such as Permutation 8. Alternatively, a much more balanced permutation containing equal numbers of positive, neutral and negative colors such as Permutation 4 resulted from attributing a positive or negative connotation to a far greater number of colors. It may be that for some studies colors with a very high positive or negative rating may be more appropriate whereas in other investigations a broader range of somewhat lower rated colors may be a better option.
The effect of anxiety and depression on the different permutations of positive, neutral and negative colors was assessed. As can be seen from Figures
6 and
7, individuals with anxiety and depression did show different patterns of color choice compared to each other as well as healthy subjects. These figures also show that negative colors are more likely to be chosen by depressed subjects and that in most cases the higher the depression score the more likely they are to choose such a color. Another notable finding was that even in healthy volunteers with depression scores within the normal range those with higher scores more frequently chose a negative color.
It is important that if the Color Wheel were to be used to help identify depression, that the majority of patients would need to choose a mood color for it to be effective in the clinical situation. However, our results indicate that a decline in mood does seem to provoke individuals to choose a color and even in depressed individuals who did not choose a color, the anxiety and depression scores were significantly lower than in those who chose a negative color irrespective of permutation. This suggests that as anxiety and depression gets worse the individual is more likely to choose a color to describe their mood. Therefore, the more anxious or depressed a person is, the more the Color Wheel approach is likely to identify the problem. Similar trends were also observed in healthy and anxious individuals although the differences did not always reach significance. The other remarkable observation from looking at Figures
6 and
7 is that it highlights the way there is a stepwise increase in anxiety and especially depression scores as individuals choose more neutral and then negative color shades. This seems to occur irrespective of whether individuals are healthy, anxious or depressed although it is most marked for healthy subjects and least apparent in the anxious and depressed group. However, it should be noted that the depressed individuals already had relatively high scores and therefore a further stepwise increase in score would be less likely to occur as they were already scoring highly.
Another aim of this study was to try and determine which permutation would be the best for use in future investigations. Regarding the relationship between mean anxiety and depression scores and positive, neutral and negative color choice, Permutation 4 was the best at detecting depression in truly depressed individuals. Likewise, Permutation 4 was also best at detecting higher anxiety scores in both anxious and depressed individuals. Permutations 7 and 8 performed best at detecting higher, although in the normal range, depression scores in healthy volunteers but did not perform well with regard to anxiety scores in this group of individuals. It therefore appears that Permutations 4, 7 and 8 are the most effective permutations although the latter two have a very restricted color choice and only work well in healthy individuals. It is probably better to choose the permutation that works best for those with a distorted color choice and thus Permutation 4 with its wider, more balanced distribution of positive, neutral and negative colors and which works well both in anxious and depressed patients would appear to be the best choice.
With regard to future studies, the Color Wheel approach could be used in children to detect affective disorders, as communication using color might be easier for them to understand than lengthy questionnaires that contain words they may not readily comprehend. The instrument would have to be revalidated in children as their response to color may differ to that of adults. The Color Wheel could also be used to help people with communication problems or those in whom English is not their first language. However, since the majority of the population examined in this study were white and of British origin, the results may not be readily transferable to groups from different cultural backgrounds. For example, in some Eastern cultures there is a strong preference for the color white[
32] which is in contrast to what was found in this study where white was seldom chosen. Thus the Color Wheel may need to be validated in different ethnic groups and this might even possibly reveal divergences in color preferences that hitherto may not have been recognised. Lastly, it has to be born in mind that many psychologically orientated questionnaires are designed to detect either a normal or negative situation. In contrast, the Color Wheel is an instrument that not only can do that but also has the ability to identify a positive state of affairs.
Competing interests
The authors declare that they have no competing interests.
Authors' contributions
HRC participated in the design of the study, collected and analysed all the data as well as drafting the manuscript. JM advised on the statistical analysis of the data and checked the accuracy of the final results. NT participated in the design of the study, acted as PhD supervisor to HRC and reviewed and critiqued the manuscript. PJW conceived the project and participated in its design as well as finalising the manuscript. All authors have read and approved the final manuscript.