Examine source code of Berries and Cones

{
  "name": "Berries and Cones",
  "manifest_version": 2,
  "version": "4.0",
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "rgba(245, 255, 255, 1)",
      "tab_background_text": "#000000",
      "toolbar": "rgba(255, 255, 255, 0)",
      "bookmark_text": "rgba(0, 0, 0, 1)",
      "toolbar_field": "rgba(255, 255, 255, 0.09)",
      "toolbar_field_text": "rgba(0, 0, 0, 1)",
      "tab_line": "rgba(209, 2, 2, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f9847d2c-79cd-49ca-a4e7-bb76dff7bb0d}"
    }
  }
}