Examine source code of Delta

{
  "name": "Delta",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "Black_colour.jpg"
    },
    "colors": {
      "frame": "rgba(0, 0, 0, 1)",
      "tab_background_text": "rgba(209, 209, 209, 1)",
      "toolbar": "rgba(140, 152, 167, 1)",
      "bookmark_text": "rgba(0, 0, 0, 1)",
      "toolbar_field": "rgba(164, 174, 186, 1)",
      "toolbar_field_text": "rgba(0, 0, 0, 1)",
      "tab_line": "rgba(0, 0, 0, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{cb7ad993-966d-46ff-a9e6-1010a8368f5b}"
    }
  }
}