When you are not actively editing the header in Word, it fades. Headers and footers are colored since they are not in the document's type area. When you double-click inside the header or footer, the text remains normal while the body of the document fades. This makes it easy to see which part of the document is being viewed.
When you choose the header/footer option, it seems normal as you type. When you return to the main body of the document, the header and footer seem faded or screened back. This is done on purpose on the screen view so you know it's the header and footer. Normal printing will take place. Any text you enter after the first page is typed becomes part of the header or footer.
To avoid this behavior, use the "Draft" mode. This way, there is no header or footer when you're editing the document. When you are ready to publish, switch to "Publish" mode. The header and footer will then be included in the final document.
Note: Even in "Draft" mode, you can include a header and footer by typing before you start your article. They will then appear at the top and bottom of each page.
The document body is muted when you work in the header or footer, and the header and footer are dimmed when the document layer is active. This is intended to serve as a visual indication to the user. You can see through documents that use these features.
Word allows you to hide the white space (including headers and footers) at the top and bottom of a page, allowing you to put more material on the screen. It's a useful tool if you need it, but if you don't know it exists and your margins suddenly vanish, you could be confused. You won't know why the margins have vanished or how to restore them.
In a word document, I am unable to read the headers and footers.
The first few times you put information in a document's header with Word 2013, it can be a bit perplexing. The header is a separate area of the document with different restrictions than the body, where you enter the majority of your material. You cannot change the header or footer style in the normal way; instead, use the With Header and Footer tools on the Layout tab to add some text to an existing header or footer, or to create a new one.
You may believe your document lacks a header and footer because you haven't added any information to them, but Word has reserved space for them. This is known as the header/footer margin, and it is distinct from the top and bottom margins. It can be changed at any time by using one of the formatting tools found on the Home tab.
If the document has a large number of fields and your Word options are configured to highlight fields "Always," those fields will be highlighted in grey. To avoid this behavior, limit the number of fields in a theme or use the "Never" option.