Examine source code of Light Gray Theme

{
  "manifest_version": 2,
  "version": "1.2",
  "name": "Light Gray Theme",
  "theme": {
    "images": {},
    "properties": {
      "color_scheme": "light"
    },
    "colors": {
      "toolbar": "rgba(180, 180, 180)",
      "toolbar_text": "black",
      "frame": "rgb(43, 40, 40)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(219, 220, 219)",
      "toolbar_field_text": "black",
      "tab_line": "rgb(4, 4, 4)",
      "ntp_background": "rgb(180, 180, 180)",
      "ntp_text": "rgb(4, 4, 4)",
      "popup": "rgb(219, 220, 219)",
      "popup_text": "rgb(4, 4, 4)",
      "tab_loading": "red"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{39898ac4-d47f-417a-8980-9f8541a7e43d}"
    }
  }
}