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A Short Investigation into Colour Contrast Preference for Buttons

Conducted as part of the MediVoice Project (a Co-operative Project, funded by the European Commission under FP6)

by Antoinette Fennell
November 2006

A sample of n = 64 visually impaired test subjects were asked to rank four colour contrast combinations in order of preference. They were asked to judge the colours on how clear the "buttons" appear and how easy it is to see the icons.

The test included subjects with a wide variety of eye conditions. These subjects were recruited from the RNIB Scientific Research Unit database. Visual acuity was not tested during the course of this study; information on eye condition was provided by the subjects themselves. The reported eye conditions in this group included retinitis pigmentosa (n = 13), macular degeneration (n = 12), nystagmus (n = 5), vision impairment resulting from injury or illness (n = 5), glaucoma (n = 5), albinism (n = 4), hereditary (n = 2), cataract (n = 4), optic atrophy (n = 2), cone dystrophy (n = 1), neuropathy (n = 1), myopia (n = 1), more than one eye condition (n = 8). One test subject did not know the cause of her visual impairment.

It should be noted that this short study did not explore the effectiveness of the symbols using task analysis, but rather was an investigation into personal preference.

The following colour combinations were shown to the test subjects:

Combination 1:

Image of colour combination 1: black icons on white buttons with black surrounding area

Combination 2:

Image of colour combination 2: black icons on white buttons with black border and white surrounding area

Combination 3:

Image of colour combination 3: white icons on black buttons with white border and black surrounding area

Combination 4:

Image of colour combination 4: white icons on black buttons with white surrounding area

The four colour contrast combinations were presented to test subjects in the form of a printed questionnaire.

To avoid bias the order in which the images were presented was randomised. The icon pairs were presented in four randomly chosen orders; n = 14, 16, 17 and 13 test subjects saw the icon pairs in the following orders respectively: 1-2-3-4, 3-2-4-1, 4-1-2-3 and 2-1-3-4.

The results were analysed (in SPSS 14.0) using Kruskal-Wallis Test and Median Test.

There was a significant difference between the four colour contrast combinations (Kruskal-Wallis Test: Chi-square = 8.2, df = 3, p < 0.05). Further investigation revealed that Combination 1 ranked higher than the other three combinations (Median Test: Chi-square = 8.6, df = 3, p < 0.05).

In conclusion, the preferred colour contrast combination was Combination 1, representing black icons on white buttons, with a black surrounding area.


Sincere thanks to the 64 anonymous volunteers who took part in this short study.



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