This is a bit of a stretch, but classical music aficionados make a distinction between playing a work with "period" instruments vs. modern instruments. For example, an 18th century composition might most accurately be performed with instruments built to the specifications and materials of the 18th century. Modern, 21st-century instruments may have superior performance attributes, but do not reflect the original composer's intention and sound of the time, and are therefore less accurate. Of course you have many interpretations of intent and classical people have debates about which ensemble does it best, etc. etc. Somewhere in there might be an analogy about colored vs. neutral transducers.
Perhaps a better example is the fellow who mentioned the various sound signatures of different performance venues (studio, concert hall, living room, etc.). There's not really an absolute standard to achieve here, although I guess you could argue that the world's truly greatest headphones and speakers should somehow play back all those different recordings perfectly, which seems a bit unreasonable at any practical cost and design. Which brings up the core cause of audiophillia in general I suppose. So I'll stop there. Suffice to say I really like how the HD-650 sound for most applications, because or in spite of the coloration, such as it is.