How do you not know it’s actually in the recording?In my case I was there when the recording was made.
What you mean when you say (whether it’s a speaker or amp or preamp) it’s darker or warmer or softer or leans to the brighter side of neutral?Most of audiophile conversation in this regard is referring to distortion. Its distortion that causes solid state amps to sound bright (which is to say it sounds a bit like when a treble control is turned up; turning down a treble control causes things to sound 'darker') and harsh. 'Warm' is often caused by the 2nd and 3rd harmonics and is more often associated with tube amplifiers, the 2nd in particular.
Both are colorations. Because brightness and harshness is annoying and fatiguing, its arguable that erring towards lower ordered harmonics (which are less annoying and to which the ear is far less sensitive) could be construed as 'more neutral'. But you have good reason to be suspicious; if you were not in the vicinity when the recording was made there really isn't any way to know what is right. To get around that you simply have to play a lot of records and on a lot of systems :) If you attend live concerts and know what the instruments sound like, that is really helpful.