Examine source code of classic dark theme

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "classic dark ",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-011-d53e0d0d1538ed554a90e056a2f04eca.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(34, 34, 34)",
      "toolbar_text": "rgb(143, 143, 143)",
      "frame": "rgb(33, 33, 33)",
      "tab_background_text": "rgb(133, 149, 155)",
      "toolbar_field": "rgb(72, 72, 72)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(66, 66, 66)",
      "popup": "rgb(33, 33, 33)",
      "popup_text": "rgb(158, 158, 155)",
      "ntp_background": "rgb(33, 33, 33)",
      "tab_loading": "rgb(66, 66, 66)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{7fe2c6da-a8bc-409b-87f6-4aeb3ec99b2e}"
    }
  }
}