Customize color in header area

Hello,

How can I change the header color to white? I went into the editor and tried to change it manually, but it didn't work. My site is harvardheal.org

Thanks!

 

Paste this code in Custom CSS
Appearance > Theme Option > Styling Option > Custom CSS

Code:

.wrapper {
background: red;
}
.header {
background: red;
}

Inplace of "red" put your color code.