Examine source code of Magic Cube

{
  "theme": {
    "images": {
      "theme_frame": "RubikTheme.png"
    },
    "colors": {
      "frame": "#8c8787",
      "tab_background_text": "#0f1445"
    }
  },
  "version": "2.0",
  "name": "Magic Cube",
  "manifest_version": 2,
  "description": "For users who like to venture out and build cubes can now have it as well in firefox."
}