Examine source code of Dark mode 2

{
  "name": "Dark mode 2",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "New Bitmap Image (2).jpg"
    },
    "colors": {
      "frame": "rgba(0, 0, 0, 1)",
      "tab_background_text": "rgba(255, 3, 3, 1)",
      "toolbar": "rgba(122, 122, 122, 1)",
      "bookmark_text": "rgba(59, 78, 219, 1)",
      "toolbar_field": "rgba(250, 249, 235, 1)",
      "toolbar_field_text": "rgba(18, 18, 17, 1)"
    }
  }
}