Examine source code of Retro Purple

{
  "name": "Retro Purple",
  "manifest_version": 2,
  "version": "5.0",
  "theme": {
    "images": {
      "theme_frame": "3343092-1992620183.jpg"
    },
    "colors": {
      "frame": "rgba(40, 22, 41, 1)",
      "tab_background_text": "rgba(151, 136, 166, 1)",
      "toolbar": "rgba(40, 11, 41, 0.51)",
      "bookmark_text": "rgba(151, 136, 166, 1)",
      "toolbar_field": "rgba(70, 48, 71, 0.44)",
      "toolbar_field_text": "rgba(151, 136, 166, 1)",
      "tab_line": "rgba(151, 136, 166, 0.15)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{35ff482f-0503-4574-b19f-147db2a7c274}"
    }
  }
}