Although he had not practised for a long time, Debussy still had a delicate touch and supple fingers which seemed to mould the sound that was overtaken by the rapidity of his soft, agile hands, and to spread it out smoothly in fluid, transparent layers. [Priest p. 49]
Play very Russian. Russians play very IN to the note, not on the surface, other wise it will sounds like blah blah... no energy, no power. That is softly.Russians plays 'hard', with energy. When they play Bach, Mozart or Rachmaninoff. It is the good way.
As a russian singing teacher told me once (Arcady Volodos by the way), tone is much more a matter of "hearing" the colour of it than actually using a certain technique to produce it.