Examine source code of Master Class

{
  "theme": {
    "images": {
      "theme_frame": "EncabezadoFirefox.png"
    },
    "colors": {
      "frame": "#0505eb",
      "tab_background_text": "#fafafa"
    }
  },
  "version": "2.0",
  "name": "Master Class",
  "manifest_version": 2,
  "description": "Master Class"
}