The problem with those definitions is that they don't really exist. According to that, "warm" is a more intense version of "dark" which is a consistently smooth downward gradient from bass to treble, a negative relationship between frequency and intensity. Frankly, I don't know of ANY headphones that actually applies to. Not a single one. And CERTAINLY none of the headphones mentioned in this thread, all of which have bass humps (with an early dropoff) of varying degrees followed by treble spikes of one kind or another. The closest I can think of would be the SE846 but that's pretty extreme and also varies wildly depending on filter/mod/tip usage.
So even if we go by what that dictionary says, the HD600 cannot be called "warm" whatsoever, and if we were to put sort of a "trend line" on the HD600 versus the HD650 and K712 it would absolutely be less warm still because its overall tilt is less pronounced. So here we are, using all of these various words and nomenclature and then linking to a glossary of terms that contradicts how they've been used in the thread.
...what now?