Examine source code of Purple Dark

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Dark Purple",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right bottom"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(0, 0, 0, 0.57)",
      "toolbar_text": "rgb(245, 245, 245)",
      "frame": "rgb(0, 0, 0)",
      "tab_background_text": "rgb(132, 131, 131)",
      "toolbar_field": "rgb(19, 19, 19)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(67, 13, 133)",
      "popup": "rgb(21, 21, 21)",
      "popup_text": "rgb(236, 236, 236)",
      "icons": "rgb(158, 79, 255)",
      "toolbar_field_border": "rgb(67, 13, 133)",
      "tab_loading": "rgb(67, 13, 133)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{162bfe85-4e13-4af5-be49-eb5b71c9c001}"
    }
  }
}