Is there any way to remove the colored bars at the top and bottom of the acknowledgment page? I know I can style the message using standard HTML, but I can't figure out anyway to remove or change the colored bars at the top and bottom. I would be happy with a blank page white page with just my message on it, actually. So, the ability to remove the bars and have a blank page would be fine as well.
We've had some requests to allow user formatting of the entire 'thank you'/form completion page, but I don't believe the ability has been implemented yet. I'll talk to the developers and see if they have any workaround for you at the moment.
Also let me know if you think I've misunderstood your question.