Change the default rpBackground color to match the footer.

@callahad - I give you the review.

The note from Shorelander is:

>  Hi Shane,
>
>  I don't think we should add the noise back. As far as default colors, if the darker grey is default then I would
>  suggest lightening it up. Still darker than the left, but lighter than it is now.
>
>  Thanks
>
>      Stephen

fixes #3677