Change Header Layout, Colors, and Height
To change the header layout, navigate to Appearance->Customize->Header & Navigation->Position & Style, and select your desired setting from the Header Layout select field. There are two options:
To change the colors of the header, use the other fields in this panel.
If you choose to go with a narrow header, keep in mind that the header will only show icons. So make sure that you have selected and icon for each of your menu items.
You will also need to upload a small logo under Customize->Header & Navigation->Logos.
To set your site logo image, navigate to Appearance->Customize->Header & Navigation->Logos. Here you can upload your logo image for the main logo, narrow header, and mobile.
Your logo images should be twice as big as you want them to appear on the site. In the Header Logo Width fields enter the width of the logo image in pixels. We use this value to make sure your logo looks great on retina displays.