Examine source code of Summer Midnight

{
  "manifest_version": 2,
  "version": "1.2",
  "name": "Summer Midnight",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(233, 236, 239)",
      "toolbar_text": "rgb(32, 18, 58)",
      "frame": "rgb(32, 18, 58)",
      "tab_background_text": "rgb(233, 236, 239)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgba(255, 255, 255, 0)",
      "popup": "rgb(255, 255, 255)",
      "popup_text": "rgb(0, 0, 0)",
      "tab_loading": "rgba(255, 255, 255, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{66945065-11e8-44be-9445-89e1ee20c193}"
    }
  }
}