Examine source code of Pure as Demon!

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Pure as Demon!",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(187, 8, 8)",
      "toolbar_text": "rgb(252, 244, 245)",
      "frame": "rgb(154, 13, 33)",
      "tab_background_text": "rgb(3, 3, 3)",
      "toolbar_field": "rgb(142, 18, 21)",
      "toolbar_field_text": "rgb(245, 239, 239)",
      "tab_line": "rgb(121, 17, 31)",
      "popup": "rgb(189, 11, 31)",
      "popup_text": "rgb(248, 251, 252)",
      "tab_loading": "rgb(121, 17, 31)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{c8e117e8-617b-483f-9d2e-66a2e98fa794}"
    }
  }
}