Examine source code of Graph Backround

{
  "name": "Graph Backround",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "Black Polygons Background 01_preview1.jpg"
    },
    "colors": {
      "frame": "rgba(189, 223, 227, 0)",
      "tab_background_text": "rgba(0, 0, 0, 0.36)",
      "toolbar": "rgba(125, 125, 125, 0.56)",
      "bookmark_text": "rgba(0, 0, 0, 0.46)",
      "toolbar_field_text": "rgba(122, 122, 122, 0.84)"
    }
  }
}