# Green means GO!!

**URL:** <https://boards.straightdope.com/t/green-means-go/517527>\
**Category:** Factual Questions\
**Created:** [November 14, 2009, 4:21am UTC](https://boards.straightdope.com/t/green-means-go/517527 "2009-11-14T04:21:30Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![heavybuhbuh](https://avatars.discourse-cdn.com/v4/letter/h/b5a626/32.png) [@heavybuhbuh](https://boards.straightdope.com/u/heavybuhbuh)\
**Post date:** [November 14, 2009, 4:21am UTC](https://boards.straightdope.com/t/green-means-go/517527/1 "2009-11-14T04:21:30Z")

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How did it come to be that green meant go . Why green? Why does yellow mean caution and red mean stop? Are these colors universal everywhere in the world?

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**Author:** ![Covered\_In\_Bees](https://avatars.discourse-cdn.com/v4/letter/c/7ab992/32.png) [@Covered\_In\_Bees](https://boards.straightdope.com/u/Covered_In_Bees)\
**Post date:** [November 14, 2009, 5:19am UTC](https://boards.straightdope.com/t/green-means-go/517527/2 "2009-11-14T05:19:31Z")

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[The Master speaks.](http://www.straightdope.com/columns/read/437/who-decided-red-means-stop-and-green-means-go)

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**Author:** ![Bearflag70](https://avatars.discourse-cdn.com/v4/letter/b/8e7dd6/32.png) [@Bearflag70](https://boards.straightdope.com/u/Bearflag70)\
**Post date:** [November 14, 2009, 5:56am UTC](https://boards.straightdope.com/t/green-means-go/517527/3 "2009-11-14T05:56:24Z")

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Q: What does a yellow light mean?

A: Slow down.

Q: W h a t d o e s a y e l l o w l i g h t m e a n?

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**Author:** ![MeanOldLady](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/meanoldlady/32/10737_2.png) [@MeanOldLady](https://boards.straightdope.com/u/MeanOldLady)\
**Post date:** [November 14, 2009, 1:40pm UTC](https://boards.straightdope.com/t/green-means-go/517527/4 "2009-11-14T13:40:20Z")

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Or the way I drive…

Q: What does a yellow light mean?

A: Go faster.

Q: _Whatdoesayellowlightmean?_

(I don’t know how to make words look faster.)

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**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\
**Post date:** [November 14, 2009, 3:21pm UTC](https://boards.straightdope.com/t/green-means-go/517527/5 "2009-11-14T15:21:59Z")

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> [@Bearflag70](#):
>
> Q: What does a yellow light mean?
> 
> A: Slow down.
> 
> Q: W h a t d o e s a y e l l o w l i g h t m e a n?

For those of you too young to get the reference:

![](https://img.youtube.com/vi/pvn-tBeLpCk/maxresdefault.jpg)https://www.youtube.com/embed/pvn-tBeLpCk?feature=oembed&wmode=opaque

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**Author:** ![KarlGauss](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/karlgauss/32/3713_2.png) [@KarlGauss](https://boards.straightdope.com/u/KarlGauss)\
**Post date:** [November 14, 2009, 4:12pm UTC](https://boards.straightdope.com/t/green-means-go/517527/6 "2009-11-14T16:12:12Z")

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Perhaps apocryphal, but I seem to recall hearing that during the ‘[Cultural Revolution](http://en.wikipedia.org/wiki/Cultural_Revolution)’ in China (ca 1967), attempts were made to switch from the “imperialist” green/go, red/stop, to the opposite pairings (indeed, in a good Marxist-Leninist society, red _should_ mean go, no?).

The results of this little undertaking were as to be expected, and things quickly reverted back to the status quo (at least for those who survived :)).