{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T00:26:51Z","timestamp":1792110411246,"version":"4.4.0"},"reference-count":65,"publisher":"The Royal Society","issue":"2076","license":[{"start":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T00:00:00Z","timestamp":1785888000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T00:00:00Z","timestamp":1785888000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"UKRI-Wellcome Physics of Life"},{"DOI":"10.13039\/100010269","name":"Wellcome Trust","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100010269","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,8,5]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Colour constancy supports stable object colour perception across changes in illumination. Illuminant colour can be inferred from white surfaces or specular highlights, and many models adopt a \u2018brightest is white\u2019 heuristic to identify illuminant colour. We tested an alternative: observers use structured changes in the proximal image to locate highlights even when they are not the brightest elements. Using computer-rendered scenes, we manipulated the reliability of two cues\u2014brightest element and highlight geometry. Each scene showed a single textured sphere lit by multiple point lights with identical spectra. The sphere had uniform spectral reflectance, while a noise texture attenuated the reflectance by a variable scale factor. We tested three specularity levels (matte, low and mid). Observers viewed a 1.5 s animation and judged whether chromatic changes represented an illuminant or material change. Performance for matte surfaces was near chance but improved sharply with increasing specularity. Observers outperformed an ideal observer relying solely on the brightest element. When highlights landed on darker texture regions, performance improved further, contrary to the brightest-element prediction. Phase scrambling, which disrupted highlight geometry while preserving global statistics, substantially reduced performance. Overall, observers do not rely solely on the brightest element; they exploit diffuse\u2013specular regularities to resolve surface\u2013illuminant ambiguity.<\/jats:p>","DOI":"10.1098\/rspb.2026.0317","type":"journal-article","created":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T00:06:46Z","timestamp":1785888406000},"source":"Crossref","is-referenced-by-count":1,"title":["When the brightest is not the best: illuminant estimation from the geometry of specular highlights"],"prefix":"10.1098","volume":"293","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9897-8338","authenticated-orcid":false,"given":"Takuma","family":"Morimoto","sequence":"first","affiliation":[{"name":"University of Oxford, 1","place":["Oxford OX1 3EL,, UK"],"department":["Department of Experimental Psychology,"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Robert J.","family":"Lee","sequence":"additional","affiliation":[{"name":"Cambridge Research Systems Ltd, 2","place":["Rochester ME2 4BH,, UK"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hannah E.","family":"Smithson","sequence":"additional","affiliation":[{"name":"University of Oxford, 1","place":["Oxford OX1 3EL,, UK"],"department":["Department of Experimental Psychology,"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"175","published-online":{"date-parts":[[2026,8,5]]},"reference":[{"key":"2026080420064255200_R1","doi-asserted-by":"crossref","first-page":"1987","DOI":"10.1242\/jeb.203.13.1987","article-title":"Chromaticity as a signal of ripeness in fruits taken by primates","volume":"203","author":"Sumner","year":"2000","journal-title":"J. Exp. Biol."},{"key":"2026080420064255200_R2","doi-asserted-by":"crossref","DOI":"10.1167\/jov.21.8.4","article-title":"Translucency perception: a review","volume":"21","author":"Gigilashvili","year":"2021","journal-title":"J. Vis."},{"key":"2026080420064255200_R3","doi-asserted-by":"crossref","first-page":"1909","DOI":"10.1016\/j.cub.2012.08.009","article-title":"The perception and misperception of specular surface reflectance","volume":"22","author":"Marlow","year":"2012","journal-title":"Curr. Biol."},{"key":"2026080420064255200_R4","doi-asserted-by":"crossref","first-page":"365","DOI":"10.1146\/annurev-vision-102016-061429","article-title":"Material perception","volume":"3","author":"Fleming","year":"2017","journal-title":"Annu. Rev. Vis. Sci."},{"key":"2026080420064255200_R5","doi-asserted-by":"crossref","first-page":"1152","DOI":"10.1038\/s41562-023-01601-0","article-title":"Material category of visual objects computed from specular image structure","volume":"7","author":"Schmid","year":"2023","journal-title":"Nat. Hum. Behav."},{"key":"2026080420064255200_R6","doi-asserted-by":"crossref","DOI":"10.1167\/17.5.7","article-title":"Visual wetness perception based on image color statistics","volume":"17","author":"Sawayama","year":"2017","journal-title":"J. Vis."},{"key":"2026080420064255200_R7","doi-asserted-by":"crossref","first-page":"20160341","DOI":"10.1098\/rstb.2016.0341","article-title":"How camouflage works","volume":"372","author":"Merilaita","year":"2017","journal-title":"Phil. Trans. R. Soc. B"},{"key":"2026080420064255200_R8","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1016\/j.cobeha.2019.07.007","article-title":"Camouflage in a dynamic world","volume":"30","author":"Cuthill","year":"2019","journal-title":"Curr. Opin. Behav. Sci."},{"key":"2026080420064255200_R9","doi-asserted-by":"crossref","first-page":"551","DOI":"10.1016\/j.cub.2019.12.013","article-title":"Iridescence as camouflage","volume":"30","author":"Kjernsmo","year":"2020","journal-title":"Curr. Biol."},{"key":"2026080420064255200_R10","doi-asserted-by":"crossref","first-page":"3258","DOI":"10.1016\/j.cub.2024.06.015","article-title":"Cuttlefish adopt disruptive camouflage under dynamic lighting","volume":"34","author":"Drerup","year":"2024","journal-title":"Curr. Biol."},{"key":"2026080420064255200_R11","doi-asserted-by":"crossref","first-page":"1408","DOI":"10.1016\/j.cub.2025.01.029","article-title":"A leaf-mimicking moth uses nanostructures to create 3D leaf shape appearance","volume":"35","author":"Kelley","year":"2025","journal-title":"Curr. Biol."},{"key":"2026080420064255200_R12","doi-asserted-by":"crossref","first-page":"1329","DOI":"10.1098\/rstb.2005.1633","article-title":"Sensory, computational and cognitive components of human colour constancy","volume":"360","author":"Smithson","year":"2005","journal-title":"Phil. Trans. R. Soc. B"},{"key":"2026080420064255200_R13","doi-asserted-by":"crossref","first-page":"674","DOI":"10.1016\/j.visres.2010.09.006","article-title":"Color constancy","volume":"51","author":"Foster","year":"2011","journal-title":"Vision Res."},{"key":"2026080420064255200_R14","doi-asserted-by":"crossref","first-page":"2475","DOI":"10.1109\/TIP.2011.2118224","article-title":"Computational color constancy: survey and experiments","volume":"20","author":"Gijsenij","year":"2011","journal-title":"IEEE Trans. Image Process."},{"key":"2026080420064255200_R15","doi-asserted-by":"crossref","first-page":"972","DOI":"10.1109\/TIP.2002.802531","article-title":"A comparison of computational color constancy algorithms. I: Methodology and experiments with synthesized data","volume":"11","author":"Barnard","year":"2002","journal-title":"IEEE Trans. Image Process."},{"key":"2026080420064255200_R16","first-page":"379","volume-title":"Proc. 2015 IEEE Int. Conf. Computer Vision (ICCV), Boston, MA, 7\u201312 June 2015","author":"Barron","year":"2015"},{"key":"2026080420064255200_R17","doi-asserted-by":"crossref","unstructured":"Bianco\n              S\n            , CusanoC, SchettiniR. 2015Color constancy using CNNs. In2015 IEEE Conf. Computer Vision and Pattern Recognition Workshops (CVPRW), Boston, MA, 7\u201312 June 2015, pp. 81\u201389. New York, NY: IEEE. (doi:10.1109\/CVPRW.2015.7301275)","DOI":"10.1109\/CVPRW.2015.7301275"},{"key":"2026080420064255200_R18","doi-asserted-by":"crossref","DOI":"10.1098\/rsfs.2018.0012","article-title":"The perception of colour and material in naturalistic tasks","volume":"8","author":"Brainard","year":"2018","journal-title":"Interface Focus"},{"key":"2026080420064255200_R19","doi-asserted-by":"crossref","first-page":"217","DOI":"10.1016\/j.cobeha.2019.10.008","article-title":"Three-dimensional stimuli and environment for studies of color constancy","volume":"30","author":"Mizokami","year":"2019","journal-title":"Curr. Opin. Behav. Sci."},{"key":"2026080420064255200_R20","doi-asserted-by":"crossref","DOI":"10.1167\/jov.23.7.8","article-title":"Color and gloss constancy under diverse lighting environments","volume":"23","author":"Morimoto","year":"2023","journal-title":"J. Vis."},{"key":"2026080420064255200_R21","doi-asserted-by":"crossref","DOI":"10.1167\/jov.24.2.12","article-title":"Color constancy in real-world settings","volume":"24","author":"Gegenfurtner","year":"2024","journal-title":"J. Vis."},{"key":"2026080420064255200_R22","article-title":"Color constancy mechanisms in virtual reality environments","volume":"24","author":"Rodr\u00edguez","year":"2024","journal-title":"J. Vis."},{"key":"2026080420064255200_R23","first-page":"1278","article-title":"Recognition and perceptual use of specular reflections","volume":"32","author":"Hurlbert","year":"1991","journal-title":"Invest. Ophthalmol. Vis. Sci."},{"key":"2026080420064255200_R24","doi-asserted-by":"crossref","first-page":"2581","DOI":"10.1016\/S0042-6989(01)00143-2","article-title":"Illuminant cues in surface color perception: tests of three candidate cues","volume":"41","author":"Yang","year":"2001","journal-title":"Vision Res."},{"key":"2026080420064255200_R25","doi-asserted-by":"crossref","first-page":"1979","DOI":"10.1016\/S0042-6989(02)00098-6","article-title":"Stereo disparity improves color constancy","volume":"42","author":"Yang","year":"2002","journal-title":"Vision Res."},{"key":"2026080420064255200_R26","doi-asserted-by":"crossref","first-page":"369","DOI":"10.1167\/3.5.4","article-title":"Surface color perception under two illuminants: the second illuminant reduces color constancy","volume":"3","author":"Yang","year":"2003","journal-title":"J. Vis."},{"key":"2026080420064255200_R27","doi-asserted-by":"crossref","first-page":"863","DOI":"10.1167\/5.10.8","article-title":"Illumination estimation in three-dimensional scenes with and without specular cues","volume":"5","author":"Snyder","year":"2005","journal-title":"J. Vis."},{"key":"2026080420064255200_R28","doi-asserted-by":"crossref","first-page":"6","DOI":"10.1167\/12.4.6","article-title":"The color constancy of three-dimensional objects","volume":"12","author":"Xiao","year":"2012","journal-title":"J. Vis."},{"key":"2026080420064255200_R29","doi-asserted-by":"crossref","DOI":"10.1167\/14.2.16","article-title":"The effects of surface gloss and roughness on color constancy for real 3-D objects","volume":"14","author":"Granzier","year":"2014","journal-title":"J. Vis."},{"key":"2026080420064255200_R30","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1007\/s10043-016-0295-6","article-title":"Do specular highlights and the daylight locus act as cues for estimating illumination color from a single object?","volume":"24","author":"Nagai","year":"2017","journal-title":"Opt. Rev."},{"key":"2026080420064255200_R31","doi-asserted-by":"crossref","first-page":"A306","DOI":"10.1364\/JOSAA.33.00A306","article-title":"Low levels of specularity support operational color constancy, particularly when surface and illumination geometry can be inferred","volume":"33","author":"Lee","year":"2016","journal-title":"J. Opt. Soc. Am. A"},{"key":"2026080420064255200_R32","doi-asserted-by":"crossref","DOI":"10.1098\/rsos.171290","article-title":"Motion of glossy objects does not promote separation of lighting and surface colour","volume":"4","author":"Lee","year":"2017","journal-title":"R. Soc. Open Sci."},{"key":"2026080420064255200_R33","doi-asserted-by":"crossref","DOI":"10.1167\/jov.20.12.4","article-title":"Specular highlights improve color constancy when other cues are weakened","volume":"20","author":"Wedge-Roberts","year":"2020","journal-title":"J. Vis."},{"key":"2026080420064255200_R34","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1038\/scientificamerican1277-108","article-title":"The retinex theory of color vision","volume":"237","author":"Land","year":"1977","journal-title":"Scient. Am."},{"key":"2026080420064255200_R35","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1111\/j.1475-1313.1992.tb00285.x","article-title":"Rules for colour constancy","volume":"12","author":"McCann","year":"1992","journal-title":"Ophthal. Physiol. Opt."},{"key":"2026080420064255200_R36","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1364\/JOSAA.18.000055","article-title":"Scene illuminant classification: brighter is better","volume":"18","author":"Tominaga","year":"2001","journal-title":"J. Opt. Soc. Am. A"},{"key":"2026080420064255200_R37","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1068\/p03sp","article-title":"Scene articulation: dependence of illuminant estimates on number of surfaces","volume":"31","author":"Linnell","year":"2002","journal-title":"Perception"},{"key":"2026080420064255200_R38","doi-asserted-by":"crossref","first-page":"2319","DOI":"10.1098\/rspb.2004.2884","article-title":"Colour constancy under simultaneous changes in surface position and illuminant","volume":"271","author":"Amano","year":"2004","journal-title":"Proc. R. Soc. Lond. B"},{"key":"2026080420064255200_R39","doi-asserted-by":"crossref","first-page":"680","DOI":"10.1167\/4.9.2","article-title":"Illuminant color perception of spectrally filtered spotlights","volume":"4","author":"Khang","year":"2004","journal-title":"J. Vis."},{"key":"2026080420064255200_R40","doi-asserted-by":"crossref","DOI":"10.1364\/JOSAA.29.00A133","article-title":"Estimating illuminant color based on luminance balance of surfaces","volume":"29","author":"Uchikawa","year":"2012","journal-title":"J. Opt. Soc. Am. A"},{"key":"2026080420064255200_R41","doi-asserted-by":"crossref","first-page":"1183","DOI":"10.1364\/JOSA.69.001183","article-title":"Chromaticity diagram showing cone excitation by stimuli of equal luminance","volume":"69","author":"MacLeod","year":"1979","journal-title":"J. Opt. Soc. Am."},{"key":"2026080420064255200_R42","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1145\/142920.134078","article-title":"Measuring and modeling anisotropic reflection","volume":"26","author":"Ward","year":"1992","journal-title":"Comput. Graph."},{"key":"2026080420064255200_R43","doi-asserted-by":"crossref","first-page":"1359","DOI":"10.1016\/0042-6989(92)90228-B","article-title":"An operational approach to colour constancy","volume":"32","author":"Craven","year":"1992","journal-title":"Vision Res."},{"key":"2026080420064255200_R44","volume-title":"Physically based rendering: from theory to implementation","author":"Pharr","year":"2016","edition":"3rd edn"},{"key":"2026080420064255200_R45","doi-asserted-by":"crossref","first-page":"2901","DOI":"10.1016\/S0042-6989(98)00225-9","article-title":"The spectral sensitivity of the human short-wavelength sensitive cones derived from thresholds and color matches","volume":"39","author":"Stockman","year":"1999","journal-title":"Vision Res."},{"key":"2026080420064255200_R46","doi-asserted-by":"crossref","first-page":"1711","DOI":"10.1016\/S0042-6989(00)00021-3","article-title":"The spectral sensitivities of the middle- and long-wavelength-sensitive cones derived from measurements in observers of known genotype","volume":"40","author":"Stockman","year":"2000","journal-title":"Vision Res."},{"key":"2026080420064255200_R47","doi-asserted-by":"crossref","DOI":"10.1167\/14.2.6","article-title":"RenderToolbox3: MATLAB tools that facilitate physically based stimulus rendering for vision research","volume":"14","author":"Heasly","year":"2014","journal-title":"J. Vis."},{"key":"2026080420064255200_R48","doi-asserted-by":"crossref","first-page":"1489","DOI":"10.1016\/0042-6989(94)90151-1","article-title":"Ultraviolet as a component of flower reflections, and the colour perception of Hymenoptera","volume":"34","author":"Chittka","year":"1994","journal-title":"Vision Res."},{"key":"2026080420064255200_R49","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1111\/j.1520-6378.1994.tb00053.x","article-title":"Measurement and analysis of object reflectance spectra","volume":"19","author":"Vrhel","year":"1994","journal-title":"Color Res. Appl."},{"key":"2026080420064255200_R50","doi-asserted-by":"crossref","first-page":"1243","DOI":"10.1098\/rstb.2000.0676","article-title":"Communication and camouflage with the same \u2018bright\u2019 colours in reef fishes","volume":"355","author":"Marshall","year":"2000","journal-title":"Phil. Trans. R. Soc. Lond. B"},{"key":"2026080420064255200_R51","doi-asserted-by":"crossref","first-page":"8151","DOI":"10.1073\/pnas.141505198","article-title":"Parallel detection of violations of color constancy","volume":"98","author":"Foster","year":"2001","journal-title":"Proc. Natl Acad. Sci. USA"},{"key":"2026080420064255200_R52","doi-asserted-by":"crossref","first-page":"947","DOI":"10.1068\/p5182","article-title":"Effect of scene complexity on colour constancy with real three-dimensional scenes and objects","volume":"34","author":"Nascimento","year":"2005","journal-title":"Perception"},{"key":"2026080420064255200_R53","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1017\/S0952523806233285","article-title":"Color constancy in natural scenes with and without an explicit illuminant cue","volume":"23","author":"Amano","year":"2006","journal-title":"Vis. Neurosci."},{"key":"2026080420064255200_R54","doi-asserted-by":"crossref","first-page":"219","DOI":"10.3758\/PP.70.2.219","article-title":"Color constancy: phenomenal or projective?","volume":"70","author":"Reeves","year":"2008","journal-title":"Percept. Psychophys."},{"key":"2026080420064255200_R55","doi-asserted-by":"crossref","first-page":"113","DOI":"10.3758\/BF03202828","article-title":"QUEST: a Bayesian adaptive psychometric method","volume":"33","author":"Watson","year":"1983","journal-title":"Percept. Psychophys."},{"key":"2026080420064255200_R56","doi-asserted-by":"crossref","first-page":"307","DOI":"10.1073\/pnas.96.1.307","article-title":"Mechanisms of color constancy under nearly natural viewing","volume":"96","author":"Kraft","year":"1999","journal-title":"Proc. Natl Acad. Sci. USA"},{"key":"2026080420064255200_R57","doi-asserted-by":"crossref","unstructured":"Lu\n              R\n            , GijsenijA, GeversT, NedovicV, XuD, GeusebroekJM. 2009Color constancy using 3D scene geometry. InProc. 2009 IEEE 12th Int. Conf. Computer Vision (ICCV), Kyoto, Japan, pp. 1749\u20131756. New York, NY: IEEE. (doi:10.1109\/ICCV.2009.5459391)","DOI":"10.1109\/ICCV.2009.5459391"},{"key":"2026080420064255200_R58","doi-asserted-by":"crossref","first-page":"3855","DOI":"10.1109\/TIP.2014.2336545","article-title":"Color constancy using 3D scene geometry derived from a single image","volume":"23","author":"Elfiky","year":"2014","journal-title":"IEEE Trans. Image Process."},{"key":"2026080420064255200_R59","doi-asserted-by":"crossref","first-page":"877","DOI":"10.1038\/47245","article-title":"Perception of three-dimensional shape influences colour perception through mutual illumination","volume":"402","author":"Bloj","year":"1999","journal-title":"Nature"},{"key":"2026080420064255200_R60","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1111\/1467-9280.00426","article-title":"Lightness constancy: a direct test of the illumination-estimation hypothesis","volume":"13","author":"Rutherford","year":"2002","journal-title":"Psychol. Sci."},{"key":"2026080420064255200_R61","doi-asserted-by":"crossref","first-page":"1171","DOI":"10.1068\/p5476","article-title":"The influence of depth segmentation on colour constancy","volume":"35","author":"Werner","year":"2006","journal-title":"Perception"},{"key":"2026080420064255200_R62","doi-asserted-by":"crossref","first-page":"770","DOI":"10.1068\/p6485","article-title":"Effect of scene dimensionality on colour constancy with real three-dimensional scenes and objects","volume":"39","author":"de Almeida","year":"2010","journal-title":"Perception"},{"key":"2026080420064255200_R63","doi-asserted-by":"crossref","first-page":"R547","DOI":"10.1016\/j.cub.2015.05.004","article-title":"Asymmetries in blue\u2013yellow color perception and in the color of \u2018the dress\u2019","volume":"25","author":"Winkler","year":"2015","journal-title":"Curr. Biol."},{"key":"2026080420064255200_R64","article-title":"When the brightest is not the best \u2014 data and code. Zenodo.","author":"Morimoto","year":"2026"},{"key":"2026080420064255200_R65","article-title":"Supplementary material from: When the brightest is not the best: illuminant estimation from the geometry of specular highlights. Figshare.","author":"Morimoto","year":"2026"}],"container-title":["Proceedings of the Royal Society B: Biological Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/royalsocietypublishing.org\/rspb\/article-pdf\/doi\/10.1098\/rspb.2026.0317\/6155074\/rspb.2026.0317.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/royalsocietypublishing.org\/rspb\/article-pdf\/doi\/10.1098\/rspb.2026.0317\/6155074\/rspb.2026.0317.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,5]],"date-time":"2026-08-05T00:06:55Z","timestamp":1785888415000},"score":1,"resource":{"primary":{"URL":"https:\/\/royalsocietypublishing.org\/rspb\/article\/293\/2076\/20260317\/482692\/When-the-brightest-is-not-the-best-illuminant"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,5]]},"references-count":65,"journal-issue":{"issue":"2076","published-print":{"date-parts":[[2026,8,5]]}},"URL":"https:\/\/doi.org\/10.1098\/rspb.2026.0317","relation":{},"ISSN":["1471-2954"],"issn-type":[{"value":"1471-2954","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,5]]},"article-number":"20260317"}}