User blog comment:DaNASCAT/Technical Update: May 6, 2015/@comment-4129195-20150507154248/@comment-1398253-20150508083337

Yeah, the icons are dark because the code expects a light background (white, the wiki's content background colour), but thanks to the customisations, it's dark green. Perhaps they can use local CSS to force usage of the light coloured icons used on wikis with a dark background?