How to faux paint 1 wall with multiple colors?

I love color, and I am wanting to paint the top portion of a main wall in my living multiple colors, using the colors from the kitchen, dining, and entryway all on that level to pull it all together in the living room. How would I do this? Do you have to use a glazing liquid? I was thinking of using a sponge. This wall is the wall that my fireplace so and their is a chair rail on the wall so I think it would be neat to have it as an accent wall.