Examine source code of Twilight

{
  "manifest_version": 2,
  "version": "2.0",
  "name": "Twilight",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-009-f069b97f439938a011297c84464f0df6.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(25, 21, 18)",
      "toolbar_field": "rgb(21, 17, 16)",
      "toolbar_field_text": "rgb(239, 239, 239)",
      "tab_line": "rgb(25, 21, 18)",
      "popup": "rgb(25, 21, 18)",
      "popup_text": "rgb(239, 239, 239)",
      "tab_loading": "rgb(25, 21, 18)",
      "bookmark_text": "rgb(192, 109, 67)",
      "frame": "rgb(21, 17, 16)",
      "tab_background_text": "rgb(239, 239, 239)"
    }
  }
}