Examine source code of Contented Cows

{
  "name": "Contented Cows",
  "manifest_version": 2,
  "version": "6.0",
  "theme": {
    "images": {
      "theme_frame": "ContentedCowsHcopyCustom.jpg"
    },
    "colors": {
      "frame": "rgba(139, 203, 240, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(136, 202, 240, 0)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(136, 202, 240, 0.05)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(255, 255, 255, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{865cae88-64f7-46f6-905a-c5a2bc036166}"
    }
  }
}