title: Comparison of the CIELab and CIEDE2000 color difference formulas.
abstract: BACKGROUND
  Many color specification systems and color differences have been proposed to improve the correlation between color measurement and visual perception. Although color differences can be quantified using either the CIELab formula (ΔE*(ab)) or the recently introduced CIEDE2000 formula (ΔE00), which captures the perceived color difference better is unknown.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the CIELab and CIEDE2000 formulas to determine which best reflects the difference in color perception and whether color perception differs by sex.
  
  
  METHODS
  Forty participants grouped 18 dental resin disks (color range: from 73.6 to 87.5 for L*; from -1.6 to 3.4 for a*; from 18.1 to 36.6 for b*), the only requirement being that each group was formed of disks with chromatically indistinguishable colors. Each participant was free to choose the number and composition of the groups. With the results obtained, a dissimilarity matrix was generated, and nonmetric multidimensional scaling (MDS) was applied to it to obtain the coordinates of the disks within a Euclidean space.
  
  
  RESULTS
  The linear correlation coefficient between the interpoint distances of the MDS configuration (MDS_total sample) and the color differences with the CIELab formula (ΔE*(ab)) was 0.176 (P=.029), whereas with the CIEDE2000 formula (ΔE00) it was 0.289 (P<.001). For the configuration obtained in the women's group (MDS_w), the correlation between the interpoint distances and the CIELab color differences was 0.230 (P=.004), and the CIEDE2000 color difference was 0.328 (P<.001). For the configuration obtained in the men's group (MDS_m), the color differences calculated with both formulas reflected the perceived differences more poorly.
  
  
  CONCLUSIONS
  Within the limitations of this study, the CIEDE2000 formula reflected the color differences perceived by the human eye better than the CIELab formula (ΔE*ab). In addition, women were confirmed to be more sensitive than men to color differences.
authors.affiliation: Associate Professor, Department of Dentistry, School of Medicine, University of Salamanca, Salamanca, Spain. Electronic address: crisgodent@usal.es.
authors.forename: Cristina
authors.initials: C
authors.lastname: Gómez-Polo
authors.affiliation: Associate Professor, Department of Dentistry, School of Medicine, University of Salamanca, Salamanca, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Portillo Muñoz
authors.affiliation: Associate Professor, Department of Dentistry, School of Medicine, University of Salamanca, Salamanca, Spain.
authors.forename: Mari Cruz
authors.initials: MC
authors.lastname: Lorenzo Luengo
authors.affiliation: Associate Professor, Department of Statistics, Faculty of Medicine, University of Salamanca, Salamanca, Spain.
authors.forename: Purificación
authors.initials: P
authors.lastname: Vicente
authors.affiliation: Tenured Lecturer of Prosthodontics, Department of Statistics, Faculty of Medicine, University of Salamanca, Salamanca, Spain.
authors.forename: Purificanción
authors.initials: P
authors.lastname: Galindo
authors.affiliation: Associate Professor, Department of Statistics, Faculty of Medicine, University of Salamanca, Salamanca, Spain.
authors.forename: Ana María
authors.initials: AM
authors.lastname: Martín Casado
mesh_terms: D000328:Adult; D003116:Color; D003118:Color Perception; D003124:Colorimetry; D003738:Dental Cements; D005260:Female; D006801:Humans; D008297:Male
chemical_list: D003738:Dental Cements