I have met with many sellers over the years who are indecisive about painting before listing their homes for sale. I have heard emotional excuses like, "It took us so much time and planning to make that design or come up with that color and pattern, we just can't bear to paint over it". A more common response is, "Why should I paint it when I can just give the buyers a paint allowance and let them pick their own color?"
The problem is that many buyers lack the imagination to see past a color they don't like or even find offensive! Their response keeps them from imagining themselves living in that space. Paint is essential to staging.
I have worked with successful home investors who have mastered the art of "vanilla".
Paint is a low costs backdrop to appealing to buyers who want the benefit of moving into a "move-in ready" home.
On another note, in negotiations, buyers tends to inflate the costs of making cosmetic updates. They will either request a larger allowance than the seller anticipated or they expect a greater discount off the price.
The majority of buyers and sellers today have watched (even recorded) home buying/selling and remodeling shows. Time and time again buyers walk into a room and first mention the paint color.
BE PRO-ACTIVE! Paint. If a seller is on a tight budget, I typically suggest they paint the main open spaces on the walls EXCEPT the lines near ceilings and corners. Hire a professional painter to do the finishing touches. (If you are going to paint, at least make it look like a professional did it.)
The effort sellers put into the pre-listing phase can mean thousands more dollars on the final closing statement for the seller. Should a seller paint? I say,"JUST DO IT!".