User blog comment:Kirkburn/Technical Update: August 31, 2016/@comment-26402117-20160901131645/@comment-24473195-20160901140445

Perhaps you are not consciously aware of it, but colors do have meaning in all cultures of the world. In fact, some colors are associated with certain emotions, and are discouraged in certain events or tools. For example, traffic lights use different colors to signal different things. In the case of software they have specific effects on usability and accessibility. So to answer your question both professional researchers and usability experts defined what colors best suit an interface:


 * http://usabilitynews.org/aesthetics-and-usability-a-look-at-color-and-balance/
 * https://scholar.google.com/scholar?hl=en&q=usability+colors&btnG=&as_sdt=1%2C5&as_sdtp=
 * http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.127.9422&rep=rep1&type=pdf

Mediawiki developers may or may not have followed these guidelines and best practices, but it doesn't change their importance.