As a Realtor in League City, Texas, I often have clients with dramatic or brightly painted walls who are resistant to neutralizing tones prior to listing their homes.
While I can totally understand the hesitation to spend time and money on a house you are leaving behind, I think most Realtors would agree that houses with neutral colored walls show better and sell faster. I found a great tool to use in trying to convince my clients to paint some of their walls. Behr.com allows you to upload a picture of the room you are considering painting and then change the paint color so that you can visualize what the room would look like with all different colors. Sometime seeing a picture of the actual room with a different color can convince someone how much better it could look. Check it out.
It's pretty awesome... With a bit of practice, you can make the before and after look pretty good. Use it to convince your clients to paint, or use it to show a rendering of a room to a buyer so they can see the potential. And you can do this in 5 minutes to make sure you like a color you are thinking about painting!!
You may like the purple better, but I guarantee you that the majority of buyers will want the neutral. Why? Because not everyone likes purple. And their furniture may clash with the purple.