Examine source code of Red Pattern.

{
  "theme": {
    "images": {
      "theme_frame": "Untitled-2.jpg"
    },
    "colors": {
      "frame": "#ffffff",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Red Pattern.",
  "manifest_version": 2,
  "description": "This is a smiply theme for everyone who likes old victorian/gothic wall patterns. I personally think it is wonderful, and I recommend it. :) Enjoy."
}