Examine source code of dramiz - Steam

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "dramiz - Steam 1",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(25, 37, 54)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(23, 29, 37)",
      "tab_background_text": "rgb(164, 164, 164)",
      "toolbar_field": "rgb(0, 0, 0)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(33, 52, 87)",
      "popup": "rgb(26, 41, 58)",
      "popup_text": "rgb(255, 255, 255)",
      "tab_selected": "rgb(33, 52, 87)",
      "tab_text": "rgb(255, 255, 255)",
      "tab_loading": "rgb(33, 52, 87)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{80d04248-9659-4034-8853-54ca85ebd2b9}"
    }
  }
}