Recently I was looking at more IDA Pro on OS X than normally, so I experimented with themes a bit, e.g. Consonance. Then I found IDASkins. Lo and behold, there are tons of Windows IDA versions for which it has been already precompiled in the github repo, but no OS X ones.
OS X compilation in cmake files in IDASkins is marked "untested" and it is, in fact, a bit buggy. After some fiddling I got the compilation to work, although one of the resulting plugins (one for Ida 64) crashes everything, no idea why :). I'm mostly looking at 32bit ARM anyways, so one plugin is good enough for me.
The diff that made the build work is in this gist. It contains mostly cosmetic changes, plus a weird fact that "if(APPLE)" didn't work properly in the cmake I had (from homebrew?). Plus I haven't used make before :) YMMV
Plugin for 32bit OS X IDA Pro 6.8 is here.
Oh and while I am compiling plugins, here are the two precompiled WWDC plugins for the same version of IDA Pro. No tricks in compiling it from source, just stick it into "plugins" dir of IDA SDK and have a universal or i386 libcapstone.a (the one from home-brew is x64 only, I believe).