Yes. Mostly. But not altogether.
That's a definite answer.
And then... I'm not sure whether it would be voice rather than style. Come to think of it, the difference between tone, style, and voice -- and if there is one -- and how much of a difference there might be -- would be a discussion without end.
I'm also having trouble thinking of a successful published author who writes in more than one genre whose writing I've read. I want to say, Anne Rice. She wrote some novels you could call contemporary fiction and also wrote some erotica. But they are all in her voice even if the tone, mood, and style of the fiction differs.
And ... when I think about my own writing, I'm sure they're all in my voice and it's only the bells and whistles which change. I don't write in one genre unless you want to group fantasy, science fiction, and all of it's sub-genres into one genre called Speculative Fiction. Then yes, I do write in one genre.
But then, characters in novels have their unique voice and I try to make sure each of my characters has their own way about them, to demonstrate each point of view character's unique way of looking at the world with their internal dialogue, their spoken dialogue, and their use of language. How one character sees fluffy clouds shouldn't be how another one does. Or, actually, more likely, one character would see clouds and the other one wouldn't. One character would use disclaimers and qualifiers such as 'I suppose' and another would use declarative sentences. Whether said use of qualifiers versus declarative sentences translates as politeness versus arrogance or inferiority complex versus confidence depends on, perhaps, the intersection between the readers experience (the reader's personal context) and the context of the characters.
Which is to say, I have no idea.
