Scientific study into autism and color is very scarce, but is certainly a problem for some; it’s hard to say, however, for how many on the autism spectrum.
Coulter (2009) says: ‘Acute sensitivity to color has been widely reported by first-hand accounts and caretaker observations. Individuals with autism have been noted to only eat white foods or to never play with toys of a certain color.’
It’s fairly common that people on the spectrum have great difficulty with extreme colors, such as very bright, glaring and/or contrasting colors. An extreme over-sensitivity to one or more specific colors, apart from such features seems less common. An indication of the latter can be found in a poll by Marga Mostafa among parents and teachers of autistic children. (See the ‘core literature‘.) They were asked to indicate which of six environmental factors they found the most important one for impact on their children and pupils. By far the highest scored noise and spatial arrangements. None of the parents and 4% of the teachers mentioned color. This does not mean color was judged as unimportant; color just very rarely makes first place.
Individual color experiences
Lets say first and foremost that color is experienced individually: what is strongly preferred by one can be unbearable to another. For people on the spectrum both sensitivities and preferences to specific colors can be extremely strong. When designing for more than one person however, it is nevertheless necessary to try and find some general principles which usually – as with most other senses – take over-sensitivities as points of departure.
Certain colors or combinations of them can ‘feel’ as nails on a chalkboard and can cause nausea and dizziness. Such responses are not very common and highly personal. A resident of the long-stay unit of the dr. Leo Kannerhuis (see acknowledgements) who had considerable preoccupations and compulsive behavior, had a strong preference for the color yellow. It dominated her room and – to an extent – her unit as well.
‘Muting’ is often desired when applying colors, but what is ‘muted’ to one can be arousing or even stressful to someone else.
The necessity to adapt the color of spaces is stronger as the autism is more serious, for the sensitivity to color generally runs parallel to the magnitude of the autistic problems. (Something which, by the way, is true for all sensory sensitivities.) Another reason for the higher relevance of color for people at the more serious end of the spectrum is that they often have stronger preoccupations which may pertain to color as in the case of the long-stay resident just mentioned.
Color by itself (as in the blue of blue)
Next to such individual differences in perception and impact of color, more or less common responses can nevertheless be discerned: the ‘cooler’ the colors, the less the risk of stressful over-stimulation. That is to say: the blue and green end of the color spectrum is calming in comparison to the agitating effects of red and yellow at the other end. These are general tendencies, leaving room for considerable individual differences.
Dijkstra investigated wall colors in care institutions among people without autism in which the effects just mentioned were once more confirmed. However, she made the important discovery that the degree of arousal/stress depends on ‘the ability to screen out irrelevant stimuli within the environment (…). Some people have a natural tendency to effectively reduce the complexity of an environment (high-screeners), where others are not capable of this information reduction (low-screeners). Therefore, we expected that effects of environmental coloring would be moderated by people’s stimulus screening ability.’ This expectation was confirmed in her study.
Making (unconscious) decisions about what to filter out on the basis of an appraisal of a whole context is something people on the spectrum usually find very hard, if not impossible. An underlying weak central coherence comes to mind as a prime cause for this. Other autism characteristics, notably low flexibility, probably contribute as well. All in all, this would mean that people on the spectrum are significantly more stressfully aroused by colors, particularly at the warm end of the spectrum.
Some specialists do not emphasize the colors themselves but rather properties such as clarity and degree of reflection. There seems to be unanimity about a number of properties: muted and neutral colors are to be preferred. (See Henriksen et al.)
‘Explosive’ and reflecting colors are not helpful. Clear, fresh colors, on the other hand are, so are pastels. Muted colors, which are more mixed and less saturated, come over as less aggressive. All soft colors are soothing. Many residents of the Kannerhuis prefer ‘clean colors’, i.e. those which are only mixed with white.
Color in context
Apart from the colors themselves and their vividness, ‘color context’ is important, too. ‘Color context’ is the way color is combined, the lighting, the size of the surfaces, the distance between the colored area and the observer and a number of other circumstances, which together, have a significant impact on the experience of the individual. One of the Kannerhuis experts (see acknowledgements) finds this context decisive, such as where, for whom, which materials, the size of the space, because colors fade with the distance from them. She states: ‘How does the sunlight enter? Light, unmixed colors such as white, yellow and clear greens have a reflecting effect.’ ‘A low-stimuli color scheme isn’t necessarily a dull color scheme. Rather it can be a harmonious color scheme consisting of pastels and flowing lines. So it can be lively, yet quiet, acquiring a warm character. Thinking of ‘low stimuli’ one should realize that light-dark contrasts have more impact than differences in hue; so, the first thing to do is reduce contrasts where it is necessary.’
Application of these insights seem riddled by contradictions: should one start from general principles or rather from individual and idiosyncratic perceptions? How should one weigh the consequences stemming from ‘color by itself’, ‘color properties’ and ‘color in context’ against one another?
Opinions differ sometimes widely around all these questions. Employing soothing colors at the cool end of the spectrum which are muted and have low glare is nevertheless a well accepted general policy.
Here we adhere to the assumption that not much can be said about preferences for specific ‘colors as such’. This might change however if the results of a small recent study will be confirmed. Grandgeorge & Masataka compared color preferences of 29 boys with ASD with those of 38 normally developing boys and found significant differences: the latter group preferred yellow, while the ASD-group preferred green and brown. This finding highlights the controversy since it is at odds with the example given above of a whole unit where the preferred color happened to be yellow.
Given a collective use of space, general principles will tend to prevail. Simultaneously, individual sensitivities and preferences should be taken into account insofar as circumstances allow. For instance, color application in the private room of a resident of a treatment- or long-stay home should allow for indiviual preference while the collective areas will require color application that adheres to general principles. In non-collective situations such as independent living, such concessions to general principles are not necessary. Children living at home are in between these options; the seriousness of their color sensibilities will determine to what extent family members are asked to adapt.
When applying insights about color impact, one should realize that other considerations than about color as such may be in play as well. As an example Donna Williams mentions these:
– consistency in colors of walls and floors demand less tolerance for change
– even, unornamented surfaces of walls, floors and furniture reduce sensory overload and fragmentation (and additionally invite less compulsive behavior).