Change background color of The Motion Homepage A top section

First, if you are not using WordPress 4.7 or later then please install the  Advanced CSS Editor plugin and in Appearance -> Customize -> Advanced CSS Editor add the following code:

#featured-videos{
background: #fff !important;
}

If you are using WordPress 4.7 or later then you could instead add the code to the Additional CSS area in Appearance->Customizer

You could generate a color of your choice by using this website:  http://www.hexcolortool.com/