The perception of yellow in bruises

• Published in: Journal of clinical forensic medicine 2004-10, Vol.11 (5), p.257-259
• Main Authors: Hughes, V.K., Ellis, P.S., Langlois, N.E.I.
• Format: Article
• Language: English
• Subjects: Adult; Age Factors; Aging - physiology; Color Perception - physiology; Color Vision Defects - physiopathology; Colour perception; Contusions; Contusions - pathology; Female; Forensic medicine; Forensic Medicine - methods; Humans; Male; Middle Aged; New South Wales; Observer variation; Skin bruising; Wounds, Nonpenetrating - pathology
• ISSN: 1353-1131; 1532-2009
• DOI: 10.1016/j.jcfm.2004.01.007

For forensic purposes, the presence of the colour yellow in a bruise may be regarded as indicating it is not recent. However, a previous study has shown that observers may disagree in their description of the colours in a bruise. This study was designed to determine how consistent observers are in perceiving the presence of yellow. Subjects were shown a series of photographs of a bruise that had been digitally modified (Adobe ® Photoshop ®) to contain amounts of yellow that increased from 2% to 20%. The point at which subjects first perceived the colour yellow was recorded. The perception threshold for yellow ranged from 4% to 16% (mean=8.7%, median=8%) in the 50 subjects that had normal colour vision. Statistical analysis indicated that an individual's yellow perception threshold increased by 0.07% each year, but gender had no effect. The results reveal that there is variability in the perception threshold for yellow in the general population and that a subject's ability to perceive yellow in a bruise declines with age.