Examine source code of Steelmountain

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Steelmountain ",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat-x"
      ]
    },
    "colors": {
      "toolbar": "rgb(72, 80, 90)",
      "toolbar_text": "rgb(229, 229, 229)",
      "frame": "rgb(72, 80, 90)",
      "tab_background_text": "rgb(229, 229, 229)",
      "toolbar_field": "rgb(58, 58, 60)",
      "toolbar_field_text": "rgb(194, 194, 196)",
      "tab_line": "rgb(144, 144, 210)",
      "popup": "rgb(72, 80, 90)",
      "popup_text": "rgb(229, 229, 229)",
      "tab_loading": "rgb(144, 144, 210)"
    }
  }
}