Examine source code of Yazoo...

{
  "theme": {
    "images": {
      "theme_frame": "Yazzypersona.jpg"
    },
    "colors": {
      "frame": "#cfcfcf",
      "tab_background_text": "#8f9ab5"
    }
  },
  "version": "2.0",
  "name": "Yazoo...",
  "manifest_version": 2
}