Dark and laid back vs bright and forward

What do reviewers mean when they describe an amp as dark? Laid back? Forward? Bright?
It is not possilbe to reproduce a live musical performance exactly as performed in the auditorium or studio in your living room.

However, getting as close as possible to 'true to the original' is the only valid goal for the audiophile --the 'connoisseurs of coloration' reviewers (who obviously get paid by the word) notwithstanding.

The first priority to achice this goal is speaker selection appropriate to a specific listening room. Then their set-up and the sonic quality of the source material. Followed by the support components best suited to those speakers. Cables and tweaks following suit.

So, I substitute 'real', 'accurate', or 'neutral'. for the terms 'bright', and 'warm', etc., for describing degrees of 'distortion' or 'coloration'.

I also recommend trusting your own ears. Recall 'live' sounds you have heard, and compare what you hear in your system. The more dramatic is in the low frequencies. The 'boom' of a 'boom-box' makes a low frequeny sound that no known musical instrument is known for making, for instance.

The 'bass' sounds should be identifiable as the bass guitarist playing in the lower octives (which he does not always do, by the way), each pluck of a string individually identifiable, or the kick of the bass drum, short and snappy (like real), etc.

Beware the 'psycho-acoustic' phenomenon. When the telepone first came out people were quoted as saying. 'it sounds just like talking in person'. Of course the telephone is not there even yet. Shakespear wrote, 'to thine own self be true', indicating how long self-delusion has been going on in human thinking (perceiving).

When I tweak my system, or nudge the speakers a bit, and then listen (a bit harder) for a difference, it always sounds better (not just different). Of course it is no doubt the result of 'listening harder' and the tweak made no audible change at all, good or bad.

Anyway, if you have trouble remembering 'real' sounds, start listening. You will be amazed how well you can do on your own --without just resorting to the eloquent terminology of the 'connoiseurs of coloration'.
OOPS! I realy forgot to define a worm sound!

Here it goes:

A real worm sound is usually heard through larger than 100W/ch class A amplifier when on the listening distance you feel that wormth.

Not intend to blame class A amplifiers rather than just bringing definitions to reality, folks. I adore Plinius poweramps but damn, it's a hot summer comming right now!
Okay, here goes! The above terms only apply to solid state amps regardless as to how "properly designed" they are. They are all some thing or the other or a combination throughout the frequency range. However, a truly properly designed tube amp will not be any of those things. It will simply be one or another expression of music. I really think well designed tubes have only musical expressions, no transistors I've listened to ultimately express music.
If you're the real Lemmy Caution, "dark" means "bright", as "no" means "yes" (nod, that is, shake your head, to agree). Lemmy'll know what I mean. Glad to know there's still an audience for classic foreign cinema.
Everything has been said, provided words do not change their meanings, and meanings their words.