Examine source code of Catherine_

{
  "name": "Catherine",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "versuch.jpg"
    },
    "colors": {
      "frame": "rgba(0, 0, 0, 1)",
      "tab_background_text": "rgba(255, 255, 255, 0.62)",
      "toolbar": "rgba(0, 0, 0, 0.34)",
      "bookmark_text": "rgba(235, 235, 235, 0.65)",
      "toolbar_field": "rgba(255, 255, 255, 0)",
      "toolbar_field_text": "rgba(237, 237, 237, 0.49)",
      "tab_line": "rgba(158, 158, 158, 0)"
    }
  }
}