How to change background colour of "Offline Message"?

[Gimpymoo]

I change background colour but that only changes the colour behind the text, if that makes sense.

Thanks for any help.

Edit: 

Fixed.

Added to source:

<style>
body {
    background-color: rgb(xxx,xxx,xxx);
}
</body>

Well, something similiar, IPB corrected it I think which was cool.

Background colour now changed. Surely a button to change this could be added?

EDIT 2:

Nope, not fixed.

In the preview, the background is a solid colour yet when looking at the page, still not a solid background colour.

All I have in the source is:

<p><style type="text/css">body {
    background-color: rgb(250,183,0);
}</style></p><p>&nbsp;</p>

The preview shows a solid colour.

The actual page is still white.

Can someone more competent clarify if I am doing it wrong or if is a bug?

Thanks.