How To Add Header Section in Google Docs
Step 1: From the top menu select Insert → Headers & footers → Header
Step 2: In the box enter some text. Congrats, now this text will be on all pages of your document. If you want this header to be on the first page only, check the 'Different first page' checkbox. You can change the size, color, and style of header text as you wish.
How to Change Header Background in Google Docs
Step 1: From the top menu select Insert → Drawing → New
Step 2: Create a square object, and fill it color you like. Save and close.
Step 3: Drag inserted image to the Head section
Step 4: Make the image 'Behind text' and 'Fix position on page'. Stretch it to fill all empty space.
