Examine source code of Placid

{
  "theme": {
    "images": {
      "theme_frame": "persona-cool_blue-live.png"
    },
    "colors": {
      "frame": "#dbdbdb",
      "tab_background_text": "#0d2c8c"
    }
  },
  "version": "2.0",
  "name": "Placid",
  "manifest_version": 2,
  "description": "My first attempt at making a persona."
}