color
a visual attribute of things that results from the light they emit or transmit or reflect
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
Researched by: Codex + Grok
Purpose and description
Enable an AI agent to identify, compare and assess a thing's color under stated conditions and decide how that color may be reproduced, changed or used.
Colour is the appearance attribute of a visual stimulus that arises from the spectral composition of light emitted, transmitted or reflected toward an observer, is sampled by the short-, medium- and long-wavelength cone photoreceptors and organised in opponent channels, and is specified along the dimensions of hue, brightness or lightness, and colourfulness, chroma or saturation.
It can be Describe or measure a selected region's color while retaining observation conditions and uncertainty.; Compare a color with a reference using a declared method and task-specific tolerance.; Translate a color specification between declared representations and report reproduction limits.; Select or adjust a target color to support a stated visual distinction.; Detect color drift or nonuniformity and request a controlled re-observation.; Propose a change to the bearer's displayed or material color through the corresponding device or material model..
Distinguishing features
A color attribution identifies a visual appearance or color specification; identifying a pigment or material alone does not establish that appearance.
A numerical color value requires a declared encoding and interpretation context; identical channel numbers in different contexts are not sufficient evidence of identical color.
A change caused by illumination or surrounding colors must be distinguishable from a change in the bearer itself.
A color name groups appearances for communication; sharing a name does not establish a measured or perceptual match.
An achromatic appearance still falls within color; absence of a prominent hue does not mean that no color attribute exists.
Scope
+ The bearer, region and time to which a color attribution applies
+ Color appearance under specified illumination, viewing and observer conditions
+ Color measurements, names and encodings with their interpretation context
+ Spatial and temporal color variation and uncertainty
+ Color matching, reproduction and suitability for an intended distinction or task
- The full identity, geometry and lifecycle of the object bearing the color
- Pigment, dye or material composition and manufacturing processes
- Light-source engineering and complete spectral characterization
- Surface texture, gloss and transparency as independently modeled attributes
- Observer physiology, diagnosis and individual visual health
- Complete visual designs, symbolic systems and accessibility assessments
Characteristics
- Color bearer and extent
- Bearer reference; whole object, surface, region, pixel or volume; observation time Prevents a local or temporary color observation from being attributed to an entire thing indefinitely.
- Light interaction
- Emitted, reflected, transmitted, mixed or undetermined Identifies which light and viewing conditions must accompany an observation.
- Hue description
- Named hue with vocabulary and language, or achromatic, ambiguous or undetermined Supports recognizable descriptions while preserving uncertainty and naming conventions.
- Lightness or brightness descriptor
- Value on a named scale with the quantity, reference and conditions declared Distinguishes how light or bright a color appears without silently treating different quantities as interchangeable.
- Chromatic intensity descriptor
- Chroma, saturation or colorfulness on a declared scale, with the chosen quantity identified Records the strength of the chromatic appearance without collapsing distinct descriptors into one unspecified value.
- Color coordinates
- Coordinate tuple with color space, scale, reference conditions and profile where applicable Makes a numerical representation interpretable and usable for comparison or reproduction.
- Observation context
- Illumination, viewing geometry, background, observer basis and instrument or capture references Allows an agent to judge whether two color observations are comparable.
- Color uniformity
- Uniform within a stated tolerance, spatially varying, temporally varying or unassessed Determines whether one representative color adequately describes the selected extent.
- Color difference
- Value with named comparison method, reference color and observation conditions Supports explicit matching decisions rather than relying on unspecified similarity.
- Representation role
- Observed, measured, estimated, intended or nominal Separates evidence about current appearance from a target or label.
Analytical facets
- substance
- abstract
- origin
- conceptual
- agency
- inert
- mobility
- not-applicable
- scale
- not-applicable
- affordances
- observable
Also called
+154
Where this came from
oewn:2024 · CC BY 4.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 18 findings · 28 questions.
Color attribution Establishes what bears the color and whether the attribution describes appearance, evidence or intent.
An agent must know what a color statement applies to before using it to recognize or change anything.
Bearer and region
Locates the color on a thing at a relevant scale and time.
Attribution extent
Record the bearer and selected extent, including whether a single color summarizes a varying region.
- Which thing, surface, region or volume bears this color, and at what time? definition
- Does this attribution describe the whole selected extent or only a sample, dominant color or average? boundary
Appearance and intent
Separates a current observation from an assigned name or desired specification.
Attribution basis
Identify whether the color is observed, measured, inferred, nominal or intended, and retain its supporting evidence.
- Does this color statement report appearance, an instrument result, an estimate, a label or a target? definition
- Which observation, measurement, source image or specification supports the statement? provenance
Viewing conditions Records the circumstances under which the color is observed or expected to appear.
Color judgments require enough context to distinguish a changed appearance from a changed bearer.
Light and geometry
Identifies the relevant light interaction, illumination and viewing arrangement.
Optical observation context
Record whether the appearance involves emission, reflection or transmission and the conditions governing that observation.
- Is the observed light emitted, reflected, transmitted or a combination? definition
- What illumination, viewing angle and, for transmission, optical path apply to the observation? measurement
Observer and surround
Identifies the observer basis and surrounding visual context relevant to appearance.
Perceptual context
Retain the background, adaptation conditions and human or modeled observer basis needed to interpret a color judgment.
- Whose judgment or which declared observer model does this appearance description represent? provenance
- What background, surrounding colors and adaptation conditions accompanied the judgment? measurement
Color description and encoding Connects perceptual descriptions and color names to interpretable numerical representations.
An agent must communicate color without confusing names, raw values and reproducible specifications.
Perceptual description
Describes hue and other appearance dimensions using explicit vocabulary and scales.
Appearance descriptors
Record the selected descriptive terms, their meanings and any ambiguous or inapplicable hue assignment.
- Which hue name or achromatic description applies, in which language or controlled vocabulary? definition
- Which lightness, brightness, chroma, saturation or colorfulness quantities are recorded, and on what scales? measurement
Numerical representation
Makes coordinate values interpretable and traces transformations between representations.
Encoding context
Keep coordinates with their color space, range, applicable reference conditions and transformation history.
- What color space, channel range, reference white and device profile are applicable to these values? definition
- Were these values measured directly or produced by capture, conversion or estimation, and through which process? provenance
Color comparison and change Assesses matches, differences and variation over space, time and viewing conditions.
An agent needs an explicit basis for deciding whether colors match or whether a meaningful change has occurred.
Match assessment
Defines the reference, comparison conditions and acceptance criterion.
Conditional color match
Treat a match as a judgment tied to a method, tolerance and viewing conditions.
- Which reference color, comparison method and tolerance define an acceptable match for this task? measurement
- Must the match hold across different illuminants or observers, and what evidence supports that broader claim? boundary
Variation and drift
Distinguishes spatial variation and temporal drift from observation or capture differences.
Variation evidence
Record the sampling basis, uncertainty and comparability of observations used to assert variation.
- How does color vary across the selected region or observation period, and how was that variation sampled? measurement
- Could differences in lighting, viewing, capture or measurement uncertainty account for the apparent change? boundary
Color use and reproduction Relates color to a practical visual task and the means available to reproduce or alter it.
An agent must connect a color judgment to an actionable decision with explicit success criteria.
Visual task fitness
Assesses whether the color supports the intended distinction in its actual context.
Task-dependent distinction
Identify the visual distinction the color must support and the evidence required to judge its adequacy.
- Which neighboring colors or background must this color be distinguishable from, for which users and conditions? boundary
- What task-specific criterion determines whether to accept the color, adjust it or add another visual cue? action
Reproduction and adjustment
Connects the target appearance to output capabilities and verification.
Achievable target color
Record the target medium, known reproduction limits and acceptable deviation before proposing a color change.
- Can the intended display, print process or material reproduce the target color under the required viewing conditions? boundary
- If the target cannot be reproduced, which approximation is acceptable and how will the resulting appearance be checked? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Kinds and varieties
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- surface (object) colour - related colour belonging to an opaque material under an illuminant
- volume colour - colour seen in or through a transparent or translucent medium
- self-luminous / illuminant colour - colour of a light source, flame, or emissive display
- achromatic colour - whites, greys and blacks that lack hue
- structural colour - colour from interference, diffraction or scattering rather than molecular absorption
- fluorescent colour - colour that includes absorption and re-emission at longer wavelengths
- spectral colour - colour of (near-)monochromatic visible radiation on the spectrum locus
- induced colour - colour produced by simultaneous or successive contrast rather than by the local stimulus alone
- Which of these kinds and varieties hold for the sense of color this model covers, and on what evidence? provenance
Identifiers and schemes
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Wikidata - Q1075 - Item for colour as a visual perceptual property.
- CIE 1931 XYZ - X, Y, Z tristimulus (relative, typically ≥ 0) - Device-independent specification of a colour stimulus for a stated observer and illuminant.
- CIELAB (CIE 1976 L*a*b*) - L* a* b* (or L* C*ab hab) - Approximate uniform space for object-colour specification and colour difference.
- sRGB / CSS hex - #RRGGBB (8-bit per channel) or rgb(r g b / a) - Encoded display colour under IEC 61966-2-1, not a unique object-colour identity.
- Munsell Color System - Hue Value/Chroma, e.g. 5R 4/14 - Atlas-based notation still used in soils, conservation and some manufacturing.
- Natural Colour System (NCS) - S HHHH-C NNN, e.g. S 1070-Y90R - Swedish standard notation used in architecture and product design.
- Pantone Matching System - PMS code, e.g. PMS 185 C - Proprietary spot-colour product identifier, not a colourimetric space.
- RAL - RAL Classic four-digit, e.g. RAL 3020; also RAL Design - European industrial paint and powder-coating identifier.
- Which of these identifiers and schemes hold for the sense of color this model covers, and on what evidence? provenance
Standards and regulation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- CIE 15 Colorimetry - International Commission on Illumination (CIE)
- ISO/CIE 11664-1 to 11664-6 Colorimetry (standard observers, illuminants, CIELAB, CIEDE2000, etc.) - ISO jointly with CIE
- IEC 61966-2-1 Multimedia systems and equipment - Colour measurement and management - sRGB - IEC
- ASTM E308 Standard Practice for Computing the Colors of Objects by Using the CIE System - ASTM International
- ICC.1 (ISO 15076-1) Image technology colour management - Architecture, profile format, and data structure - International Color Consortium / ISO
- ISO 3664 Graphic technology and photography - Viewing conditions - ISO
- ISO 3864 (safety colours and safety signs) and ANSI Z535.1 Safety Colors - ISO; ANSI/NEMA
- National food- and toy-colourant rules (e.g. EU colour additives, US FDA color additives) govern colorants, not the appearance attribute itself
- Which of these standards and regulation hold for the sense of color this model covers, and on what evidence? provenance
Real-world use
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Specifying and accepting paint, plastics, textiles, packaging and printed matter against a standard or a ΔE tolerance
- Reproducing brand and product colour across displays, print and physical goods via ICC profiles and device characterisation
- Coding meaning in traffic signals, piping, electrical wiring, and workplace safety signs
- Assessing ripeness, spoilage, grade and contamination in food and agriculture by hue and chroma
- Clinical observation of skin, mucosa and sclera (pallor, cyanosis, jaundice) as a sign, not a measured colour standard
- Identifying minerals, soils (Munsell), gems and biological specimens
- Lighting design via correlated colour temperature and colour rendering of sources
- Which of these real-world use hold for the sense of color this model covers, and on what evidence? provenance
Typical measurements
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Visible wavelength (for spectral lights) - about 380-780 - nm
- CIELAB lightness L* - 0 (black) to 100 (diffuse white) - dimensionless (CIE L*)
- CIELAB chroma C*ab - 0 (achromatic) to about 100-150 for highly chromatic object colours - dimensionless (CIE C*)
- CIELAB hue angle hab - 0-360 - degree
- CIEDE2000 colour difference ΔE00 - 0 identical; ~0.8-1 just noticeable under good viewing; industrial pass often 1-3; >5 clearly different - dimensionless (ΔE00)
- Spectral reflectance factor - 0-1 (occasionally >1 with fluorescence or optical brighteners) - dimensionless (or %)
- Correlated colour temperature of a source - about 1800 (candle/very warm) to 6500 (daylight) in common use; up to ~10000 in some lamps - K
- Which of these typical measurements hold for the sense of color this model covers, and on what evidence? provenance
Failure modes and hazards
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Illuminant metamerism: two samples match under one light and mismatch under another
- Observer metamerism and congenital colour-vision deficiency, especially red-green confusion of signals and wiring
- Photofading, thermal and chemical degradation of dyes and pigments, shifting hue and losing chroma
- Geometry and fluorescence errors: 45/0 or sphere instruments miss goniochromatic or fluorescent appearance
- Reproduction failure: out-of-gamut mapping on displays and print, wrong white point, or missing colour management
- Simultaneous contrast and afterimages causing false colour judgements in inspection
- Toxic or restricted colorants (historical lead chromate, cadmium, chromium(VI) pigments; some azo dyes) as a material hazard, not a property of colour itself
- Which of these failure modes and hazards hold for the sense of color this model covers, and on what evidence? provenance
Regional variation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Basic colour-term inventories differ: e.g. Russian distinguishes goluboy and siniy as separate basic blues; Japanese ao historically covered blue-green; some languages collapse blue and green
- Trade notation differs by industry and region: RAL in much of Europe, NCS in Sweden and neighbouring architecture, Pantone in fashion and graphic arts, Munsell in US soils and some conservation practice
- Orthography and legal drafting: British/International English colour versus American English color, including in ISO dual spellings
- Safety and wiring colour codes are standardised but not globally identical (older national electrical colour conventions persist)
- Which of these regional variation hold for the sense of color this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- colourant (dye, pigment, ink) - A colourant is a material that modifies spectral absorption, scattering or emission; colour is the resulting appearance. Same colourant can yield different colours under different substrates, concentrations and lights.
- spectral power distribution / wavelength - SPD (or a wavelength) is a physical radiometric description; colour is the observer-dependent appearance. Many SPDs are metameric (same colour, different spectra).
- lightness or brightness (luminance) - Luminance and lightness are achromatic intensity quantities; colour in the full sense includes chromatic content (hue and chroma). Two lights can share luminance and still differ in colour.
- hue - Hue is one dimension of colour (red/yellow/green/blue family). Colour also comprises lightness/brightness and chromatic intensity.
- gloss, texture, and goniochromism - Gloss and surface texture change how light is spatially distributed; they are appearance attributes distinct from colour, though they alter measured and perceived colour if geometry is not controlled.
- coloration (biology) / colouration - Biological coloration names the organismal production of colour (pigment, structure, bioluminescence). Colour remains the appearance; the neighbour is the living mechanism and pattern.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of color this model covers, and on what evidence? provenance
Sources
- ILV: International Lighting Vocabulary, 2nd Edition (CIE S 017/E:2020) - Specialist definition of colour as a perceptual attribute with hue, brightness/lightness and chromatic intensity; related versus unrelated colour; colourimetric quantities.
- CIE 15: Colorimetry - Standard observers, illuminants, tristimulus values, chromaticity, CIELAB and recommended colour-difference practice.
- ISO/CIE 11664 series (Colorimetry: CIE standard observers and illuminants, CIE 1976 L*a*b*, CIEDE2000) - Normative identifiers and measurement spaces used to specify object and illuminant colour.
- Color Science: Concepts and Methods, Quantitative Data and Formulae - Physical, physiological and colourimetric account of emitted, transmitted and reflected light; metamerism; colour-matching functions.
- Color Appearance Models - Modes of colour appearance (surface, volume, illuminant, aperture), related versus unrelated colour, and appearance dimensions.
- Basic Color Terms: Their Universality and Evolution - Cross-linguistic differences in basic colour-term inventories used under regional_variation.
What the second pass must settle
- Which color appearance and measurement conventions should Vercy adopt, and which contextual fields does each convention require?
- What minimum observation evidence is sufficient for each intended use, especially when the only input is an image with unknown capture processing?
- Where should the registry boundary fall between color and neighboring attributes for fluorescent, iridescent, metallic or otherwise angle-dependent appearances?
- Which task-specific matching tolerances and distinguishability criteria should be referenced, and who has authority to select them?
- How should multilingual color names and uncertain mappings between naming systems be represented without implying exact equivalence?