Last modified: 2014-04-06 21:55:18 UTC
Since the update to MathJax 2.3, the Tex color extension seems to be no longer working. See: https://en.wikipedia.org/w/index.php?title=Help:Displaying_a_formula&oldid=595788140#Color
The update in question: https://gerrit.wikimedia.org/r/#/c/109490/4
Fixed in: https://gerrit.wikimedia.org/r/#/c/124063/