Accent Walls & Fireplace Painting, what to do?

My client has a new home, newly stripped wall paper and now they are ready to paint.
They asked me to help them in choosing the right paint colors and help them to create a modern and comfortable space. They would like an accent wall, 2-3 colors maybe in this open floor plan consisting of a living room, dining room, hallway to bedrooms and hallway to down stairs. There also in an adjacent kitchen that has a large window opening to the dining room.
And the fireplace. Should they paint it?
Let's see what it looks like now-



 
Come back to see how I create some images for them with different color options.