The Tone of a Book

I'm working on a book where the tone of the heroine is primarily humor, and the tone of the hero is alpha male/serious. What I am finding out is that the tone of my opening chapters dominated by the heroine are totally humorous and sarcastic.

Then the tone in scenes where only the hero is in are more like his character - serious with only light smatterings of humor if at all. Then when the heroine gets kidnapped and enters his world, the tone sort of blends, but despite the difficult circumstances that she runs into, humor remains the primary coping method. Especially since her outlook on life provokes him and ends up providing humor as well. At the end of the book the tone evens because they are together, and her influence on him will mean that humor will remain the dominant tone.

What I'm wondering is if it is odd to do it this way or if it will be perceived as uneven. I suppose I'll have to see how it reads once I have it all out, but my instincts say this is OK. It emphasizes his character, her character, and the progression of conflict and humor through the book.