Here on Meta the planned tag is blue. It works properly when view a topic from /latest, as well as when scrolled to the top of the topic, but is currently not working when viewing the topic itself and the header has “collapsed”. In this instance the color is black, and only turns blue on mouse hover.
That is very true, there are a few places though it does make sense, when overriding select2 styles and anything else from a third party vendor. But stock elements that discourse creates, I 100% agree, it shouldn’t use !important.