"The web site has a off white background with black text. There is a horizontal menu at the top that fills the screen 95% horizontally and 10% vertically. The horizontal menu has a navy blue background with white text. There is a logo on the left of the horizontal menu filling 25% of the screen horizontally and 5% vertically. There are five menu items to the right of the logo image in the horizontal menu."

That's probably a little more verbose than it needs to be. But it could be a combination of CV, tapping into the renderer and traversing the DOM in order to best describe a page. Then if my screen reader isn't cutting it and I'm feeling lost I can just have the current view described to me.