Tone is in the fingers. I have been hearing many words spoken on this statement for years now. No one seems to ever come to a definitive answer for which side is correct. It's been rather unsatisfying and underwhelming for my personality which thrives on closure, so I have come up with an answer to at least satisfy myself. We will see if tone really is or is not in the fingers, or at least if I think so or not.
On one hand, I can see where people are coming from. Nothing is more disappointing than hearing a quality piece of kit showing nothing for it's pedigree because some bedroom rock star is showing just how out of tune he can pull off bends and how poorly he can play Smoke On The Water or Master Of Puppets. It's utterly vexing to hear amps that you view as wonderful, being reduced to an over-sized and overpriced practice amp. Then it's simply amazing to see a seasoned guitarist work his or her magic on utterly average and affordable gear and get marvelous sounds out of it. Many would understandably say that tone comes from the fingers, and with good reason.
On the flip side, could good playing make a Fender Twin Reverb sound like an Orange AD30? Could your playing make a Bogner Uberschall sound like a Vox AC30? Would your pick technique and phrasing transform a Marshall JCM800 into a Mesa Boogie Dual Rectifier? Would your finesse in bending and trills make the Rickenbacker or Gretsch into the Vox sound like a Paul Reed Smith into a Splawn Quickrod? The answer is obviously no. You could sound as good or bad as you care to sound, but the sound that is in your fingers is going to sound like that sound under the context of the gear you use. You will always sound like you, but you will not transform gear into gear that it isn't.
The conclusion? Your quality of sound and uniqueness is in your fingers. You can't sound like Stevie Ray Vaughan playing a Strat into a Fender tube amp, but you can certainly sound like YOU playing a Strat into a Fender tube amp. The gifted guitarist will always sound like the gifted guitarist, but his shrill and buzzy practice amp will never sound like his roaring Marshall stack. So if your playing is bad, don't blame the guitar or amp. On the other hand, if your amp is too bright for your style, don't blame your technique...turn down your treble.