It appears, at least to me, from reading the responses that there is not an overall consensus on the definition of these terms, as well as other audio terms; this really doesn't surprise me. The list of audio terms is outrageously enormous which just adds confusion, IMO.
One says Neutral is ideal another says Neutral is boring; one says warm is good another says warm is not good.
Looking at some of the definitions given at the Stereophile link can further the confusion.
It is no wonder there are many disagreements.
FWIW -
neutral - Free from coloration.
warm - The same as dark, but less tilted. A certain amount of warmth is a normal part of musical sound.
analytical - Very detailed, almost to the point of excess.
dark - A warm, mellow, excessively rich quality in reproduced sound. The audible effect of a frequency response which is clockwise-tilted across the entire range, so that output diminishes with increasing frequency. Compare "light."
light - Lean and tipped-up. The audible effect of a frequency response which is tilted counterclockwise. Compare "dark."
coloration - An audible "signature" with which a reproducing system imbues all signals passing through it.
(As you can see, some definitions need others to define themselves! At least in audio slang.)