Examine source code of my grey

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "my grey",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(218, 220, 220)",
      "toolbar_text": "rgb(9, 9, 9)",
      "frame": "rgb(175, 177, 177)",
      "tab_background_text": "rgb(13, 13, 13)",
      "toolbar_field": "rgb(249, 249, 249)",
      "toolbar_field_text": "rgb(31, 31, 31)",
      "tab_line": "rgba(208, 208, 208, 0)",
      "popup": "rgb(255, 255, 255)",
      "popup_text": "rgb(25, 25, 26)",
      "tab_loading": "rgba(208, 208, 208, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{00930a19-cb66-4964-b04b-0bc2cbe23d72}"
    }
  }
}