Examine source code of Birds up there

{
  "name": "Birds up there",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "birds.png"
    },
    "colors": {
      "frame": "rgba(229, 230, 232, 1)",
      "tab_background_text": "rgba(75, 181, 0, 1)",
      "toolbar": "rgba(66, 133, 116, 0.54)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(153, 193, 194, 0.7)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(3, 3, 3, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{34807f17-bd47-4cda-8e0e-63bd95ca79fb}"
    }
  }
}