Examine source code of Plume Nouveau

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Plume Nouveau",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-018-0ca3dfc7bb661ec53999d358812ce0ab.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(78, 84, 87)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(45, 47, 49)",
      "tab_background_text": "rgb(179, 183, 188)",
      "toolbar_field": "rgb(179, 183, 188)",
      "toolbar_field_text": "rgb(24, 25, 26)",
      "tab_line": "rgb(15, 41, 236)",
      "popup": "rgb(145, 146, 153)",
      "popup_text": "rgb(23, 24, 25)",
      "icons_attention": "rgb(238, 214, 66)",
      "popup_border": "rgb(41, 146, 87)",
      "popup_highlight_text": "rgb(103, 135, 145)",
      "popup_highlight": "rgb(238, 241, 244)",
      "sidebar_border": "rgb(31, 121, 149)",
      "sidebar_highlight_text": "rgb(241, 241, 10)",
      "sidebar_highlight": "rgb(96, 94, 108)",
      "sidebar_text": "rgb(255, 255, 255)",
      "sidebar": "rgb(68, 68, 71)",
      "tab_background_separator": "rgba(12, 12, 13, 0.72)",
      "tab_selected": "rgba(111, 112, 135, 0.72)",
      "toolbar_bottom_separator": "rgb(118, 93, 223)",
      "toolbar_field_border_focus": "rgb(188, 29, 15)",
      "toolbar_top_separator": "rgb(118, 93, 223)",
      "toolbar_vertical_separator": "rgb(122, 113, 166)",
      "tab_loading": "rgb(15, 41, 236)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{899fc54f-48e8-40ad-95fa-12c2a555c314}"
    }
  }
}