Examine source code of Steamed

{
  "name": "Steamed",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "steamed.png"
    },
    "colors": {
      "frame": "rgba(76, 88, 68, 1)",
      "tab_background_text": "rgba(240, 240, 240, 1)",
      "toolbar": "rgba(62, 70, 55, 1)",
      "bookmark_text": "rgba(196, 181, 80, 1)",
      "toolbar_field": "rgba(76, 88, 68, 1)",
      "toolbar_field_text": "rgba(240, 240, 240, 1)",
      "tab_line": "rgba(196, 181, 80, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{61380820-0076-4e19-be76-f38c18c2d618}"
    }
  }
}