Examine source code of Music Sheet

{
  "theme": {
    "images": {
      "theme_frame": "sepia_top.png"
    },
    "colors": {
      "frame": "#2470a3",
      "tab_background_text": "#2470a3"
    }
  },
  "version": "2.0",
  "name": "Music Sheet",
  "manifest_version": 2,
  "description": "This is a combination of sepia colors with some transparencies\n\nenjoy"
}