I disagree. The reference is real life. If you have a recording, and you know what it is supposed to sound like approximately one inch from the ears (where the drivers of most headphones are, and if that's where your mics are), reference headphones are ones that recreate that soundwave as accurately as possible. Ones that deliberately colour (ones that accentuate the presence or attenuate the sibilance regions, for example, or play up the midbass to trick bassheads into thinking there is moar base), are not reference headphones.
Of course, this leads me to be very confused about the Sony MDR-V6/-7506, because I do consider them to be reference headphones in terms of bandwidth, once you mentally compensate for the colouration they introduce.