Examine source code of \tree theme

{
  "name": "gaming",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "Ein_Sof_Emanation_Infinite_Tree_Life_Noah_Bradley.jpg"
    },
    "colors": {
      "frame": "rgba(255, 255, 255, 1)",
      "tab_background_text": "rgba(143, 126, 126, 1)",
      "toolbar": "rgba(120, 88, 88, 1)",
      "bookmark_text": "rgba(199, 199, 199, 1)",
      "toolbar_field": "rgba(201, 201, 201, 1)",
      "toolbar_field_text": "rgba(87, 82, 82, 1)"
    }
  }
}