Practice Innovations
Wound healing is a continuum and wounds often contain a mixture of tissue types with various colors. Medical photos are used in the assessment, documentation and treatment of wounds.1,2 Inconsistencies in technique and technical variability of photographic devices cause substantial color errors that misrepresent clinical observation,2,3,4 decrease quality of documentation,1 cause delays in diagnosis,5,6 and improper conclusions.3,7 This research, from a database of 50,900 photos taken at 14 facilities (inpatient and outpatient) in the US 12/1/21 – 12/15/23, identifies the discernible visual inaccuracy in color and potential clinical confusion caused by inaccurate photo colors in assessment of different tissue types.
Methods:
A color chart with a tracking number was placed into the photo field. Studies have shown that a color chart in the photo can be used to measure color accuracy.3 The color chart contains known target colors that are measured using the Red, Green and Blue (RGB) color system. The database was searched for the clinically relevant colors, Black, Yellow, and Red, on the Wound Healing Continuum.8 Color calibration software was used to detect the color chart and calculate the RGB color detected. Each color was 3-dimensionally plotted.
Results:
The 3-dimensional RGB plotting identified 11,644 unique Black, 29,897, unique Yellow and 27,016 unique Red RGB colors. There is visually discernible color variation for Yellow and Red. The Yellow shifts toward Orange or Green with as small as a 10% color change and darkens to dark Green at 50% change. Red lightens toward pink at 20% change and darkens to Brown/Black at 40% change The color differences for Black miniably changes under 30% change and begin to lighten to Yellow, Green and Red at 60% color change.
Discussion:
The color chart, RGB measurement and 3-dimensional RGB plotting identified significant color variation for Black, Yellow and Red. The discernible difference for Yellow and Red appear to have the greatest probability of clinical confusion of tissue types based on color inaccuracy. Black had high variability, however the clinical impact would appear to be less confusing. Color inaccuracy makes precise, verifiable color calibration necessary for photos to properly represent the live observed wound.4 While a paradigm for assessing medical image color quality as well as technical and technique standards are not fully evolved,1,2,3 this research documents the importance of accurate color and the potential clinical impact.