This works as of io.js v2.0.0. https://github.com/iojs/io.js/blob/v2.0.0/CHANGELOG.md#2015-05-04-version-200-rvagg
Thanks to @bramstein for creating these formulae! https://twitter.com/bram_stein/status/556357864038883328
It didn’t work in OS X 10.10 anymore, but it seems OS X 10.10.1 does support it. Ref. 4471e27.
It improves the display in OS X Terminal.app. http://ethanschoonover.com/solarized/vim-colors-solarized Ref. #425.