Examine source code of Private Browsing Gray for Android Phones

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#45494e",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Private Browsing Gray for Android Phones",
  "manifest_version": 2,
  "description": "This theme is designed to make the design of normal browsing on Android phones match the darker design of private browsing, the only remaining difference being the color of the address bar itself. The upper right corner is slightly darker than the rest to compensate for the transparency in that part of the UI. Unfortunately, it doesn't work in tablet mode with visible tabs; only phone mode with the single-button tab switcher."
}