We have fixed the about page issue just created the above content block again .
Now if you put your content in "Fill width resizable column" then it will appear with the background white .However if you put your content in "Fillscreen Stripe with container" then it would pick up the background of the site which is not set by you as of now.
Please also note that you are using the wplms points system child theme which is also the wplms white theme .
In this theme the background must be set to white and the unit page pick ups the default background of the site .
to make the unit page white either add the css :
.pusher {
background: #FFF;
}
OR
Set the backgruond of site as white from wp-admin ->appearance ->customize