Examine source code of Fantasma GTK

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Fantasma",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-000-5672c42860d5b06e1058dc477397f3ef.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(21, 21, 21)",
      "toolbar_text": "rgb(143, 143, 143)",
      "frame": "rgb(32, 32, 32)",
      "tab_background_text": "rgb(140, 140, 140)",
      "toolbar_field": "rgb(13, 13, 13)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(35, 205, 179)",
      "popup": "rgb(40, 40, 40)",
      "popup_text": "rgb(140, 140, 140)",
      "icons": "rgb(35, 205, 179)",
      "ntp_background": "rgb(21, 21, 21)",
      "popup_border": "rgb(35, 205, 179)",
      "popup_highlight": "rgb(35, 205, 179)",
      "sidebar_border": "rgb(35, 205, 179)",
      "sidebar_highlight_text": "rgb(35, 205, 179)",
      "sidebar_highlight": "rgb(35, 205, 179)",
      "toolbar_field_border_focus": "rgb(35, 205, 179)",
      "tab_loading": "rgb(35, 205, 179)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{5cb08a1d-5f3b-440e-b6bb-529b30e183d2}"
    }
  }
}