Background color vs out-of-bounds

Is it possible to have choice of color for out-of-bounds from the background.
I have 2 attachments to explain what I mean.
The background landscape allows pictures, text boxes, etc. to exceed the boundaries.
I have to do 400% exam after placements to make sure I’m inside the line.
If one chooses a color (I chose black for this web page) it is on the background AND also on the out-of-bounds.
Just checking to see if it is possible or suggest it as a possibility update for Sparkle in the future.
Thank you Duncan

sparkle-1

I’m a bit confused with your post @golden1one?

If you keep your image plus its border within the boundary then all will be OK.
You can also have the image to the edge and give the border say 6px (this will hang over the fixed-width edge) but it is AOK to do so.

With border colour…
If you untick Same On All Sides you will see that you can individually choose the colours of the borders plus individually their widths.

I just tested this out. I put a “Box” behind everything with the color/background of choice.
The Sparkle workspace keeps the white/ gray. I also made the Box "Move with Page Bottom.
Adding the “Border” to the Box can also have advantages to help with visual markers.
Thank you FlaminFig
I was just using the Background Fill [In my case black] making everything black for a workspace on this project. If there was a workspace color is what I meant.