Examine source code of ETR_test

{
  "name": "ETR_test",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "Untitled.png"
    },
    "colors": {
      "toolbar": "rgba(80, 85, 87, 1)",
      "toolbar_field": "rgba(139, 149, 150, 1)",
      "toolbar_field_text": "rgba(74, 74, 74, 1)",
      "frame": "rgba(52, 59, 62, 1)",
      "tab_background_text": "rgba(222, 222, 222, 1)",
      "bookmark_text": "rgba(255, 255, 255, 1)"
    }
  }
}