Page as a widget with transparent background

Hello everyone,
First of all great work on the Enfold theme, really like it!
I’m fairly new to WP and I’ve created a ‘sitemap’ Page with all the pages & links that I want to add in every page of the site.
With “Pages in Widgets” plugin I can have this ‘sitemap’ Page as a widget (to make it easy for me to add it to every page).
All good so far but in the site pages where I want to I add this widget, there is already an image background and I want my ‘sitemap’ to be ‘transparent’ so it integrates seamlessly.
I’ve tried a number of different things but because the ‘sitemap’ pages has the default style, aka black background I see the black background (or whatever other color I chose) but can’t seem to make it transparent.
How do I do this? I believe I need to change something to the section of the ‘sitemap’ page (where the colors are defined) or add something to the CSS but what do I need to change?
Many thanks for your help!
Pegnio.