Examine source code of Outlook Lite

{
  "name": "Outlook Lite",
  "manifest_version": 2,
  "version": "3.0",
  "theme": {
    "images": {
      "theme_frame": "1x1.png"
    },
    "colors": {
      "frame": "rgba(10, 10, 10, 1)",
      "tab_background_text": "rgba(92, 185, 159, 1)",
      "toolbar": "rgba(10, 10, 10, 1)",
      "bookmark_text": "rgba(92, 185, 159, 1)",
      "toolbar_field": "rgba(10, 10, 10, 1)",
      "toolbar_field_text": "rgba(92, 185, 159, 1)",
      "tab_line": "rgba(92, 185, 159, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{7f0d2d9a-6dfb-4929-9d3d-4949bfc0a152}"
    }
  }
}