Exactly, Tom. It is impossible to say which power cord is non-colored, or accurate, or whatever, if such little differences like speaker toe-in or tilt (the latter, as I vividly experienced last night) matter that much. When and how do you know that your system is a "neutral substrate" on which to test neutrality of an inserted component?
Yes, you can try to avoid components that are *obviously* colored, but between two "neutral" components, how do you know which one sounds more "neutral"? When it comes down to it, this "neutrality" thing is all pretense that does not stand up to scrutiny.
Also, quite obviously, one person's neutrality is another person's colored sound, and vice versa.
The only thing you can gauge is if a system or component allows you to hear the most differences between recordings as possible. This means it doesn't impart too much color of its own, which would lead to a sameness across recordings. But "neutrality", no color of its own? Nah.
Also, how does anyone know how a given recording is supposed to sound or what the recording engineer had in mind? It's impossible to know. Anyone who pretends to be able to chase "accuracy" in that respect should read up on the "Circle of Confusion" by Sean Olive.
Instead of "accurate" or "neutral", a much better criterion is "believable". That gets you somewhere, at least in comparison with live unamplified music.
Yet that still has a lot of subjectivity in it as well, since different people hear the same live sound differently, and prioritize different aspects of it in their judgment of its gestalt. And thus they transfer a range of live sounds differently into a frame of "believability" against which to judge the sound of a system.