Google's developer pages have not traditionally been very snazzy. The dev site served its purpose, and that's it. Now it's suddenly a completely material affair. Included in the redesign is the Nexus factory image page that you've probably visited a number of times (or almost daily).
Different parts of the dev site have different color schemes, but they all have a distinctly material vibe. The main Android page has a gray header, but the Nexus images have a bright blue one. If you go to the Android Pay section, it's green like the color of money.
The tables on the Nexus image page are still not awesome looking, but the table of contents is now expanded on the right and it floats when you scroll down. None of this is going to make a big difference in your life, but the next time you look for a Nexus image only to find that it's not out yet, you can at least enjoy the bright colors.