I think it is a matter of taste. I have mostly the same flooring througout my house, a light--white reall laminate. I am DELIBERATELY going to do the stairs a dark color--a walnut similar to my furniture. I agree that w/ the bedroom doors closed you don't see it any way! Think of carpet--perople almost ALWAYS do a different color/type in the bedrooms. Why not w/ the wood!

My philosophy is that the only things decor-wise that don't work are those things you hate. Multiple colors help to define the border of the rooms -- I actually like taking a bit of a chance there. But that's just me. If you want, one thing you might consider is doing something fun at the entry way of each room -- such as if you have kids, stain their names at the front of the door. Or, take a piece of floorboard in both colors and do a checker board pattern of the dark and light pieces at the doorjam. This might help the flow into the room...