House painting question for homeowners

The house we bought is a split level so the living room leads into the dining room on one side and on the other side it leads to the front door & hallway (open) and then the stairs up to the bedrooms level. Basically, it's all wide open except for the kitchen. So my question is...if we want to paint, do you think we have to paint the entire area all the same color? If not, where and how do you end the color and start with the next color? I could live with the living room & dining room the same color but the living room into the hall and the walls leading upstairs...then I have to paint the entire upstairs hall the same color too. If I cant figure out where to end the color, we are going to go with cream walls. Our couch is cream colored, the rug is cream colored....our wood is light....I think we need some color!

I dont know if I explained this clear but if you know split levels you probably have an idea of the layout.

Thanks in advance.

Liz, my parents own a huge split level, so I am familiar w/the layout - but I also know that there are some variations. Can you post of few snapshots, so I have a reference point?

For onw, I think that you can do the one common wall between the LR/DR a deeper accent color, and then keep the other walls in a lighter, more neutral tone.