Examine source code of Brown Bears OP

{
  "name": "Brown Bears OP",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "firefox23.jpg"
    },
    "colors": {
      "frame": "rgba(82, 61, 34, 1)",
      "tab_background_text": "rgba(204, 168, 114, 1)",
      "toolbar": "rgba(153, 121, 73, 1)",
      "toolbar_field": "rgba(204, 168, 114, 1)",
      "toolbar_field_text": "rgba(82, 61, 34, 1)"
    }
  }
}