I agree with Jeff and Hunter. Tone as a lot to do with the hands. The more you "own" your instrument the better it/you will sound.
I have had a fender american strat for 6 years now and I remember when I purchased it. It sounded ok but nothing like stevie ray vaughan's strat :) (he's the main reason why I bought a strat).
But 6 years later, lots of practice and hard work, I'm a lot better and a lot more confident, witch shows in the guitar's sound.
I recently changed the pick ups also for a more vintage 60's/70's sound. That also helped getting "The" strat sound.
I heard Buddy Guy say once that the reason why Stevie Ray Vaughan had such a great tone was because he showed the guitar who was the boss. He "owned" the instrument.
Off course strings will help with the sound but the player makes the biggest difference.