tgd on "[Plugin: Visual Form Builder] Can't change background color of the form"

Best approach is to enclose the shortcode in <div> tags with a class or ID, then target that <div> to change the background color.
<div class="vfb-form">[vfb id='1']</div>
or
<div style="background-color:#e5e5e5;">[vfb id='1']</div>
**Inline styles are not the best approach, but usable.