If your characters are the lens through which the reader experiences your story, and you the writer are the glassmaker, then vocabulary makes up the grains of sand which create the glass. Likewise, tone is the mold into which you pour your hot glass to set the lens.
Some grains will be hard, rough, imperfect; and, poured into a straight-edged mold, would make a wonderful lens for, say, a gritty detective story. Some will be dark, and smooth, and sharp, combined in a rough mold that produces a lens that is uneven and hard to see through, making it suitable for gothic romance. Some will be filled with glitter, poured into a star-shaped mold, ideal for magic and fantasy.
Your combination of Voice, Vocabulary and Tone create the Narrative Voice that is unique to your work and your book.