Examine source code of rainbow ribbon--

{
  "theme": {
    "images": {
      "theme_frame": "rainbowribbon.png"
    },
    "colors": {
      "frame": "#5f467d",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "rainbow ribbon--",
  "manifest_version": 2,
  "description": "rainbow ribbon arc-en-ciel ruban colors couleurs"
}