Examine source code of silly

{
  "name": "silly",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "life.png"
    },
    "colors": {
      "frame": "rgba(203, 171, 214, 0.88)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(123, 92, 209, 0.8)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(213, 168, 250, 0.73)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(0, 0, 0, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f0422ee8-966c-4c69-b436-3c02abe16d96}"
    }
  }
}