Style – sum of the choices that writers make (including document presentation, sentence structure and word choice).
Tone – the impact on the reader (customer-focused, informative, sincere etc).
Consider the tone of a brochure, regional newspaper, fashion journal, scientific journal, poem, maintenance manual. Each seeks acceptance from a specific audience. Each makes specific style choices to connect with this audience to achieve its objectives.
What attitudes towards your customers are you reflecting through your tone and the style choices that produce this result?