Examine source code of dark realtree

{
  "name": "dark realtree",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "dark realtree.png"
    },
    "colors": {
      "frame": "rgba(0, 0, 0, 1)",
      "tab_background_text": "rgba(0, 0, 0, 1)",
      "toolbar": "rgba(64, 60, 51, 1)",
      "bookmark_text": "rgba(0, 0, 0, 1)",
      "toolbar_field": "rgba(34, 30, 25, 1)",
      "toolbar_field_text": "rgba(148, 141, 124, 1)",
      "tab_line": "rgba(0, 0, 0, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e159cde5-2b02-46f3-a1f5-6ea02042a8eb}"
    }
  }
}