Examine source code of nightfall

{
  "theme": {
    "images": {
      "theme_frame": "love.jpg"
    },
    "colors": {
      "frame": "#000000",
      "tab_background_text": "#f1f299"
    }
  },
  "version": "2.0",
  "name": "nightfall",
  "manifest_version": 2,
  "description": "This is my first.. Hope it turns out right. :) Enjoy!"
}