Summarize this article in one sentence.
You'll find this in the upper-left corner of the page, just right of the Colors tab. It's on the left side of the page. This will prompt a copy of your theme to download onto your computer in a compressed folder. If you don't want to save your theme, skip this step. It's a green button at the top of the page. You may have to click "Continue" in the bottom-left corner of teh Chrome browser if prompted. This prompt will appear at the top of the Chrome window. Doing so installs your theme. Click the "New Tab" button to the right of the current tab, or press Ctrl+T (⌘ Command+T on a Mac). This will allow you to see your new theme in all of its splendor. The "New Tab" page will allow you to see all aspects of your theme, including your selected images and colors. If you don't like your theme, you can revert it to the Chrome default theme by clicking ⋮ in the top-right corner of Chrome, clicking Settings, and clicking RESET TO DEFAULT to the right of the "Themes" heading, which is near the top of the page.

Summary:
Click the Pack tab. Click Pack and Download Zip File. Click Pack and Install. Click Add theme when prompted. Open a new tab. Review your theme.