Examine source code of Only Mixed

{
  "theme": {
    "images": {
      "theme_frame": "header.jpg"
    },
    "colors": {
      "frame": "#f2f2f2",
      "tab_background_text": "#fcfcfc"
    }
  },
  "version": "2.0",
  "name": "Only Mixed",
  "manifest_version": 2,
  "description": "In fact of this is my first Persona and I'm not a pro in making designs it's not very good, but i want to make more because it's fun :D"
}