Hmmm, 25 years of doing IC design work at Bell Labs ( you may have heard of them, they invented the transistor
), 20 years of selling high-end audio (both tube and solid state), EE and Comp Sci degrees, and I've never seen any citation (and I'll go back to Keroes and Williamson) where the purpose of a tube is to "color the sound". So could you please enlighten me as to where you discovered the purpose of a thermionic device? And as to where it was discovered that semiconductor based devices are so devoid of this purpose?
Are you ready to argue the sonic impact of even order versus odd order harmonics? Have you seen Scott Frankland's research concerning the distortion spectrum of triodes vs. other devices at low power levels? I'll give you a hint - at low levels DHTs are superior to all other devices.
Now, since this is a forum for HOT TUBS, please resond via PM so as to not bother everyone else.