Open the Navbar Widget (dashNavbar: an adornment, so it cannot open as a Text Window) to change the color of your actual navigation bar and to set its nature as either static or fixed. (A static navbar scrolls with the rest of the page, up and away. A fixed navbar stays on top.) By default the navbar is static. To make it fixed, hit ⌘5 and set its $Sticky to true.

Because dashNavBar is an adornment rather than a note, you cannot open it as its own Text Window. Use ⌘5 to open it in the Text Pane.