Where do different languages put the line between green and blue?

Four arrangements in the recorded languages

One green term and one blue term, divided by hue, is the arrangement of Mandarin Chinese, Hungarian, Czech, Finnish, Estonian. A second line inside blue, drawn by lightness, appears in Russian, Japanese, Spanish; in Spanish it holds for Uruguay only, and in Japanese the light-blue term is recent. A term that covers green and blue together is recorded for Vietnamese, Welsh, Irish (Old and Middle Irish), Dani, Berinmo, Himba (a variety of Herero), Tsimane': as the only term for the region in Vietnamese and Dani, beside narrower terms in Welsh and medieval Irish, and as two interchangeable words for monolingual Tsimane' speakers. For Modern Greek, Italian, Turkish, Korean the lexicon holds records for one side only, because the research read concerned the two blues or the two greens; that is a gap in the records, not in the languages.

Where the hue line falls when there is one

A study that had Mandarin speakers in Taipei name the same 330 chips previously named by Japanese and American English speakers could compare the green–blue line directly. The Mandarin and Japanese blue categories matched closely (a correlation of 0.98), and each matched the English one less well (0.89 and 0.90). The English line sat one column of the chart, 2.5 units of Munsell hue, further towards green: English green was slightly smaller and English blue slightly larger. The authors attribute the shift to English speakers' use of 'teal' for the colours between. So two languages can both 'have green and blue' and still disagree about a band of blue-greens, which is where an English reader's teal, turquoise and cyan live.

Second lines: lightness inside blue, yellowness inside green

The languages with two or three blue terms divide by lightness, and the published best examples show how far apart the terms sit. For 31 Tuscan speakers the mean best example of celeste was at L* 70, of azzurro at 62 and of blu at 31: the two lighter terms are close and blu is far below. In Uruguay a light-blue stimulus at L* 68 was celeste for 85–91% of students; in Spain and Mexico nearly everyone called it azul. Russian speakers each place the siniy–goluboy line at a slightly different lightness, and it shifts with the range of blues on show. Korean draws its second line elsewhere, between a yellow-green term and a green term, inside what English calls green.

A boundary where English has none

Berinmo and Himba each have a term across green, blue and purple and a warm term that reaches into the yellowish greens, so their boundary falls inside English green and English's green–blue line falls inside one of their terms. Asked to pick the odd one out of three samples, Himba speakers chose in line with their own boundary on 76% of trials and English speakers were at chance for it; at the green–blue line English speakers followed the boundary more than Himba or Berinmo speakers did. Kay and Regier accepted these results and compared Berinmo's boundaries with those of 110 World Color Survey languages, finding them typical: the lines differ from English and still fall where many languages put theirs.

What the boundary experiments measured, and how they have held up

The best-known result is that Russian speakers discriminated two blues faster when the pair straddled the siniy–goluboy line, for hard pairs only, and that a verbal task done at the same time removed the advantage. Accuracy was about 96% for Russian and English speakers alike. A 2020 re-run of the tasks found no speed advantage. In Greek speakers a brain response to unattended changes was larger for a light-to-dark change in blue than in green, a pattern English speakers did not show; that is one study of forty people. Korean speakers searched faster across their yellow-green boundary, and when the same group measured the smallest differences speakers could detect, Korean and English speakers did not differ anywhere. The effects are real in some tasks, small, tied to language being available during the task, and not a change in discrimination.

Why one row per language is too coarse

The table below gives each language one row, and each row hides variation the sources document. Italian has two basic blues in Verona and Alghero and three in Tuscany, with different words taking the light end. Spanish has two in Uruguay and one elsewhere. Mandarin qīng is a specific blue-green on the Mainland and an uncommon, vague word in Taiwan. Monolingual and bilingual Tsimane' speakers use the same two words differently. And analyses of individual speakers in the World Color Survey find several naming systems coexisting within one language. A row describes the speakers a study sampled.

The data

How to check it yourself

1. For a language in the World Color Survey, open its naming data and look at where individual speakers changed term along the green-to-blue rows.
2. For any claim that a language 'has no word for blue', find out whether it has a term covering blue with something else, and what speakers add to it when they need to be specific.
3. For a claim about perception, check which measure was used: reaction time, grouping, memory or threshold. Only the last tests what can be told apart.
4. Check whether the result has been repeated, and by whom.

What the evidence says

Each statement is labelled by kind — established fact, a standard’s requirement, observed market data, a convention, or Colourwise’s own interpretation or analysis — with the strength of the evidence behind it.

• Colourwise analysisLimited evidence

  Of 19 recorded languages with a term in the green-to-blue region, 5 have one green and one blue term, 3 also divide blue by lightness, 7 have a term across green and blue, and 4 have records for one side only.

  Based on: Each record with a part in the region was classified by Colourwise from its coverage; the pattern is read from the terms the cited literature treats as basic, contested, emerging or regional, or from all recorded terms where none has been assessed.

  Caveat: Counts records, not vocabularies. 'One side only' reflects what the research read covered, and the lexicon is a sample chosen for the quality of its sources.

  Source: Basic color categories in Mandarin Chinese revealed by cluster analysis (Journal of Vision 20(12): 6, 2020); Basic Color Terms (BCTs) and Categories (BCCs) in three dialects of the Spanish language: interaction between cultural and universal factors (Frontiers in Psychology 9: 761, 2018); Differences in color naming and color salience in Vietnamese and English (Color Research & Application 28: 113–138, 2003); Color categories: evidence for the cultural relativity hypothesis (Cognitive Psychology 50: 378–411, 2005)

• FactModerate evidence

  In naming of the same 330 Munsell chips, the green–blue boundary of American English speakers lay one hue step (2.5 Munsell hue units) towards green of the boundary found for Mandarin speakers in Taiwan and for Japanese speakers.

  Caveat: Three separate studies with the same chips; the attribution to the English 'teal' category is the authors' explanation, not a test.

  Source: Basic color categories in Mandarin Chinese revealed by cluster analysis (Journal of Vision 20(12): 6, 2020)

• FactModerate evidence· Tuscany, Italy

  For 31 Tuscan-born participants the mean CIELAB lightness of the chips chosen as best example was 70.26 for celeste, 61.87 for azzurro and 30.80 for blu, and the three distributions differed significantly in lightness.

  Caveat: A small regional sample; other Italian locations gave two basic blue terms.

  Source: Florence “blues” are clothed in triple basic terms (i-Perception 13(5), 2022)

• FactModerate evidence

  In an odd-one-out task Himba speakers made choices consistent with the dumbu–burou boundary on 76% of trials, while English speakers were at chance for that boundary; at the green–blue boundary English speakers made more boundary-consistent choices than Himba or Berinmo speakers.

  Caveat: Small samples from small communities, and a measure of grouping, not of discrimination. Kay and Regier argue the boundaries involved are typical of the world's languages.

  Source: Color categories: evidence for the cultural relativity hypothesis (Cognitive Psychology 50: 378–411, 2005); Color naming universals: The case of Berinmo (Cognition 102: 289–298, 2007)

• FactModerate evidence

  Russian speakers showed a reaction-time advantage for blues that crossed the siniy–goluboy boundary, removed by verbal interference, with accuracy near 96% in both language groups; a 2020 repetition of the tasks did not find the advantage.

  Caveat: The two studies disagree, and the 2020 paper has a corrigendum whose content was not read.

  Source: Russian blues reveal effects of language on color discrimination (PNAS 104: 7780–7785, 2007); Russian blues reveal the limits of language influencing colour discrimination (Cognition 201: 104281, 2020)

• FactModerate evidence

  Thresholds for detecting a colour difference did not differ between Korean and English speakers and were not lower at category boundaries.

  Source: Thresholds for color discrimination in English and Korean speakers (Cognition 112: 482–487, 2009)

Related questions

Is the green–blue line in the same place for all English speakers?

No. English speakers disagree about the band between, which is why teal, turquoise and cyan exist as words and why naming studies of English find a separate teal category for many speakers.

Does a language with one word for green and blue have a best example of it?

Speakers do choose best examples, and they vary. Tsimane' speakers' two green-blue words shared one most-chosen chip, and in Himba the best examples chosen for a single term ranged widely between people.

Which is more common across languages, splitting blue or merging it with green?

The sources read here do not give a count for the world's languages. A single green-or-blue category is one of eight recurring categories found in World Color Survey data; two basic blues are documented for a smaller, mostly European and East Asian set.

Related topics

Go further

Sources

• Basic color categories in Mandarin Chinese revealed by cluster analysis (Journal of Vision 20(12): 6, 2020) — Journal of Vision (Association for Research in Vision and Ophthalmology) (Primary research)
• Basic Color Terms (BCTs) and Categories (BCCs) in three dialects of the Spanish language: interaction between cultural and universal factors (Frontiers in Psychology 9: 761, 2018) — Frontiers in Psychology (Frontiers Media) (Primary research)
• Differences in color naming and color salience in Vietnamese and English (Color Research & Application 28: 113–138, 2003) — Color Research & Application (Wiley) (Primary research)
• Color categories: evidence for the cultural relativity hypothesis (Cognitive Psychology 50: 378–411, 2005) — Cognitive Psychology (Elsevier) (Primary research)
• Florence “blues” are clothed in triple basic terms (i-Perception 13(5), 2022) — i-Perception (SAGE) (Primary research)
• Color naming universals: The case of Berinmo (Cognition 102: 289–298, 2007) — Cognition (Elsevier) (Primary research)
• Russian blues reveal effects of language on color discrimination (PNAS 104: 7780–7785, 2007) — Proceedings of the National Academy of Sciences (Primary research)
• Russian blues reveal the limits of language influencing colour discrimination (Cognition 201: 104281, 2020) — Cognition (Elsevier) (Primary research)
• Thresholds for color discrimination in English and Korean speakers (Cognition 112: 482–487, 2009) — Cognition (Elsevier) (Primary research)
• Singing the Russian blues: An argument for culturally basic color terms (Cross-Cultural Research 39: 10–38, 2005) — Cross-Cultural Research (SAGE) (Academic)
• Etymological Dictionary of the Russian Language (Max Vasmer; Russian edition, online) — ΛΓΩ lexicography.online (digitised text of the Trubachev translation) (Reference work)
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• Basic colour terms in Modern Greek: Twelve terms including two blues (Androulaki and colleagues, Journal of Greek Linguistics 7: 3–47, 2006) — Journal of Greek Linguistics (Primary research)
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• Từ điển Việt–Việt (entry xanh), Tra Từ — Soha Tra Từ (VCCorp) (Reference work)
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• Geiriadur Prifysgol Cymru: A Dictionary of the Welsh Language (entries glas, gwyrdd, llwyd) — University of Wales (Academic)
• eDIL: Electronic Dictionary of the Irish Language (entries glas, gorm, úaine) — eDIL project (Academic)
• Preliminary study of basic colour terms in modern Hungarian (Linguistica Uralica 43(2): 102–123, 2007) — Linguistica Uralica (Estonian Academy Publishers) (Primary research)
• Basic colour terms in five Finno-Ugric languages and Estonian Sign Language: a comparative study (Uusküla, Hollman and Sutrop; Journal of Estonian and Finno-Ugric Linguistics 3(1): 47–86, 2012) — Journal of Estonian and Finno-Ugric Linguistics (University of Tartu Press) (Primary research)
• The basic colour terms of Czech (Uusküla; Trames 12(1): 3–28, 2008) — Trames: Journal of the Humanities and Social Sciences (Estonian Academy Publishers) (Primary research)
• Basic Color Terms and Basic Color Categories (C. L. Hardin; chapter 11 of Backhaus, Kliegl and Werner, eds, Color Vision: Perspectives from Different Disciplines, 1998) — Walter de Gruyter (chapter text hosted by the University of California, San Diego) (Academic)
• Color categories are not universal: replications and new evidence from a stone-age culture (Journal of Experimental Psychology: General 129: 369–398, 2000) — Journal of Experimental Psychology: General (American Psychological Association) (Primary research)
• Color naming across languages reflects color use (PNAS 114: 10785–10790, 2017) — Proceedings of the National Academy of Sciences (Primary research)
• Concepts are restructured during language contact: the birth of blue and other color concepts in Tsimane'-Spanish bilinguals (Psychological Science 34: 1350–1362, 2023) — Psychological Science (SAGE) (Primary research)
• World Color Survey data archives — University of California, Berkeley (Department of Linguistics) (Academic)
• World Color Survey color naming reveals universal motifs and their within-language diversity (PNAS 106: 19785–19790, 2009) — Proceedings of the National Academy of Sciences (Primary research)

Reviewed 6 October 2026. Colourwise summarises its sources in its own words and does not reproduce standards text or proprietary colour data. Spotted an error? Tell us.