Examine source code of Dark forest

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Dark forest",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(0, 0, 0, 0.03)",
      "toolbar_text": "rgb(230, 230, 230)",
      "frame": "rgb(49, 51, 51)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(26, 26, 26)",
      "toolbar_field_text": "rgb(230, 230, 230)",
      "tab_line": "rgba(230, 230, 230, 0)",
      "popup": "rgb(20, 21, 21)",
      "popup_text": "rgb(230, 230, 230)",
      "ntp_background": "rgb(237, 237, 237)",
      "popup_border": "rgb(26, 26, 26)",
      "tab_selected": "rgb(15, 15, 15)",
      "toolbar_top_separator": "rgba(133, 123, 207, 0)",
      "tab_loading": "rgba(230, 230, 230, 0)"
    }
  }
}