I understand your point, but I would like to say that the sky, when you start to understand atmosphere and light is not blue. It is never just blue. Look at it on any given day, and you will see all the colors of the spectrum from cool or warm gray to yellow to greenish blue to red and so on. To say the sky is blue as a reference point is just limiting and misleading and not educational. But the color of the sky is a good, if not a great, example of amplifiers. I think amplifiers, the beauty of the sounds they all make, is much like that of the beauty of the sky. Limitless in color, tonality, purity of hue and intensity. And we cannot say one skyline is better than another. If really seen deeply, they are all quite stunning.
BTW I used to think solid state amplifiers sounded the best. I picked up a good, maybe not great, vacuum tube amp that I adore much more than the solid state amp. When I went to an audiophile buddy’s house he picked up a Bel Canto class d amp that he luvs. I cannot stand the sound of it, but I did not tell him. Beauty of sound is in one’s own brain. That’s it... really but I suppose anyone can learn to better at listening.