Row width problem

Hi. I started using Pagebuilder this week. I seem to have a problem which none of the many codes I found on different forum posts could resolve, thus I am writing you.

When I apply a colour to the row, it automatically extends beyond the site right/left margins. It is set on full-width as you suggested. I tried all other forms just in case, but what I need is for the width to end where my site ends, the inner border and not the background border.

I am using Sela theme.

Could you help please?

Thanks a lot

Ana