I recently repainted the interior of much of our house. I really like the Harmony paint from Sherwin-Williams. It's no-VOC and has very low odor, which was important to me for the animals. (Paint fumes can kill birds) I went with two tones of beige in the living room, with the darker on the far wall. It's warm and cozy without being overpowering. I went with the crazier, bolder colors in the other rooms of the house. You can always add your color on the moldings or with the draperies. A lot of those paint places will give you samples of colors you want to try, and you can take those home and paint test areas to see what the color will actually look like on the wall and give you an idea of which you'll like best. It can look so much different on a wall than it does on a paint chip, trust me! LOL For covering sharpie, I'd recommend using a primer before you put down the actual paint.

Or how about a mural? Several of the home stores have those, and they look nice. I have a big jungle one here on the wall behind my computer desk and love it.