Are tubes really “warm”?

Time and again I read posts that claim/assume that tubes sound “warm.” I have not found this to be the case. Having owned many high quality tube amps and preamps, I find that tube electronics present more natural highs than many ss designs. But warm?? Not in my experience. Can someone explain what it is about the tube sound that many consider “warm?”
Ag insider logo xs@2xcakids
You can take top 3 ss amp designs in the world, hook em up to highly colored (crappy/high distortion/high fatigure, muddy/murky/not warm, but HOT as hell), and you'll end up with a  pile of _____
Now take 3 top tube designs in the world , with same highly colored speakers,,and you'll at lesat get some semblance of a  live stage experience. 
This is the point i am trying to emphasize.
World's very best ss designs can not match worlds finest tube designs. In all areas of  sonic fq resolution/sound stage/live experience. 
I now believe that good body, tone richness and a good sense of dimension to stereo sound stage illusion images are more a function of the qualities of the music, the quality of the recording and the quality of the reproduction system as a whole rather than the inclusion or exclusion of tubes in the audio chain. I believe absolutes in this hobby are best avoided.

Hello mozartfan,

     Apparently, you seem to have an absolute inclination and preference toward absolute thinking in this audio hobby.  I've learned through personal experience that claims of audio absolutes are of little merit, are rarely reliable and cause the closure of an individual's mind to new ideas, discoveries along with a voluntary forfeiture of the very process of continued learning and growing itself.  Well, good luck with that.

Note that Kaitty's said his rig is a Sony Discman through Grado SR80s without earpads, so there's that. 
NO! And transistors don't sound cold!