The better the prep, the better the results! Here is a great color that works with the colors you mentioned
http://houzz.com/photos/1291372

Here are the existing colors. The floor stays the walls go.

To me these look pinker than they are perhaps because I'm taking photos at night and the lighting in there isn't great

id go with a taupe or a very light beige. Stay away from anything brown or dark beiges.

I agree with the sanding recommendation as the sponged texture will still show even when painted with 1-2 top coats. Another nice neutral color is Sudan Sand. My Sherwin Williams store has the color on file...and I've even used Sudan Sand as the tint for their Venetian Plaster product. It's a very versatile, neutral color that really works well in many spaces and varying design styles.

P.S. Sudan Sand is a Glidden color.