Examine source code of Polished Gray

{
  "manifest_version": 2,
  "version": "2.0",
  "name": "Polished Grey",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-002-609370e89a219e0548ac5ef6b4a7dd2e.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(72, 73, 78)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(2, 2, 11)",
      "tab_background_text": "rgb(177, 177, 160)",
      "toolbar_field": "rgb(226, 226, 212)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(136, 205, 35)",
      "popup": "rgb(49, 52, 83)",
      "popup_text": "rgb(215, 226, 239)",
      "ntp_background": "rgb(154, 145, 91)",
      "popup_border": "rgb(252, 64, 21)",
      "toolbar_field_border": "rgb(255, 165, 0)",
      "toolbar_top_separator": "rgb(154, 155, 192)",
      "tab_loading": "rgb(136, 205, 35)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{48f0595d-821c-45cb-8bff-837e96c87177}"
    }
  }
}