Examine source code of Nebulous

{
  "manifest_version": 2,
  "version": "1.1",
  "name": "Nebulous",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-011-d53e0d0d1538ed554a90e056a2f04eca.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(0, 0, 0, 0.1)",
      "toolbar_text": "rgb(159, 168, 182)",
      "frame": "rgb(57, 66, 77)",
      "tab_background_text": "rgb(112, 120, 126)",
      "toolbar_field": "rgb(45, 50, 55)",
      "toolbar_field_text": "rgba(203, 210, 219, 0.92)",
      "tab_line": "rgba(255, 33, 5, 0)",
      "popup": "rgba(57, 66, 77, 0.88)",
      "popup_text": "rgba(230, 230, 230, 0.93)",
      "button_background_hover": "rgba(133, 139, 147, 0.12)",
      "icons_attention": "rgb(172, 179, 189)",
      "icons": "rgb(171, 186, 196)",
      "popup_border": "rgba(34, 25, 77, 0)",
      "popup_highlight_text": "rgb(57, 66, 77)",
      "popup_highlight": "rgb(180, 187, 197)",
      "tab_background_separator": "rgba(44, 0, 255, 0)",
      "tab_loading": "rgba(255, 255, 255, 0)",
      "toolbar_bottom_separator": "rgb(57, 66, 77)",
      "toolbar_field_border_focus": "rgba(0, 0, 0, 0)",
      "toolbar_field_border": "rgb(45, 50, 55)",
      "toolbar_field_highlight_text": "rgb(57, 66, 77)",
      "toolbar_field_highlight": "rgb(206, 214, 225)",
      "toolbar_field_text_focus": "rgb(206, 214, 225)",
      "toolbar_top_separator": "rgb(49, 56, 66)",
      "toolbar_vertical_separator": "rgba(203, 210, 219, 0.15)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{3cbead21-875d-4f39-87a2-7bf0be931319}"
    }
  }
}