How to change color of background

Background color is override by CSS code from style.css. You need to remove the below code from style.css and then background color will work. For set background color: Go To > Appearance > Customize > Color.

#header-text-nav-container {
	background-color: #FFFFFF;
}

#main {
    background-color: #ffffff;
}

Hope this will work on your site.
Thanks

Thank WEN Solutions.

But still some positions do not change color, please see link.

Looking forward to get help

Thanks you!

Where white spot is seen, inspect on browser and add the background color for each class. If you are not so familiar with CSS, Would you please provide the URL of your site so that we can suggest you more easier.

Thank You

To WEN Solution!
Thanks you very much