Examine source code of Horde Theme

{
  "name": "Horde Theme",
  "manifest_version": 2,
  "version": "3.0",
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#242424",
      "tab_background_text": "rgba(209, 209, 209, 1)",
      "toolbar": "rgba(26, 26, 26, 0.26)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(240, 240, 240, 1)",
      "toolbar_field_text": "rgba(36, 36, 36, 1)"
    }
  }
}