&gt; red means cancel&#x2F;go back&#x2F;stop&#x2F;error. This is something that was learned, not something that was known by instinct.<p>Well...[1][2] There are <i>some</i> precedents for red being a no-go colour even in nature. Which is likely why we use it as a stop colour. It would be interesting if someone knows of a significant number of cultures that use it as a &quot;go ahead&quot; colour. I mean, the samples are probably skewed because everyone has been a colony these days but still.<p>[1]: <a href="http:&#x2F;&#x2F;www.noaa.gov&#x2F;features&#x2F;resources_0109&#x2F;images&#x2F;fire1.jpg" rel="nofollow">http:&#x2F;&#x2F;www.noaa.gov&#x2F;features&#x2F;resources_0109&#x2F;images&#x2F;fire1.jpg</a>
[2]: <a href="http:&#x2F;&#x2F;museumvictoria.com.au&#x2F;spidersparlour&#x2F;images&#x2F;en000008.jpg" rel="nofollow">http:&#x2F;&#x2F;museumvictoria.com.au&#x2F;spidersparlour&#x2F;images&#x2F;en000008....</a>