Examine source code of Simple Grey

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Simple Grey",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-005-f5f3cf677b1f132c75ddc7bd319dd1fc.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(75, 75, 75)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(105, 105, 105)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgb(67, 101, 191)",
      "tab_line": "rgb(98, 102, 183)",
      "popup": "rgb(95, 95, 95)",
      "popup_text": "rgb(255, 255, 255)",
      "tab_loading": "rgb(98, 102, 183)"
    }
  }
}