Examine source code of Dev Edition Darkened

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Dev Edition Darkened",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(12, 13, 13, 0.6)",
      "toolbar_text": "rgb(186, 189, 189)",
      "frame": "rgb(26, 26, 26)",
      "tab_background_text": "rgb(215, 223, 223)",
      "toolbar_field": "rgba(4, 25, 44, 0.5)",
      "toolbar_field_text": "rgb(222, 226, 226)",
      "tab_line": "rgb(249, 249, 252)",
      "popup": "rgb(1, 12, 23)",
      "popup_text": "rgb(122, 185, 244)",
      "button_background_hover": "rgba(11, 11, 11, 0.7)",
      "icons": "rgba(95, 200, 223, 0.6)",
      "popup_border": "rgb(238, 238, 244)",
      "tab_selected": "rgba(0, 5, 6, 0.3)",
      "tab_text": "rgb(245, 245, 249)",
      "toolbar_bottom_separator": "rgb(0, 0, 3)",
      "tab_loading": "rgb(249, 249, 252)"
    }
  }
}