Here's a pic of my oak stair treads and Brazilian cherry floors. (granted this will not be the final color of the Brazilian cherry floors)
What we did is take the sample home, get a scrap piece of oak... try a couple different stains.. and see which one matches the best and how many coats. We ended up using Cobalt cherry stain (it was at lowes). I've also heard of people mixing stains to get the right color.
Don't worry about the color of the floor- it will change. Let the sun shine in if you want it to move faster