Examine source code of Polygons!

{
  "manifest_version": 2,
  "version": "3.0",
  "name": "Polygons-3.0",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center center"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(225, 234, 239)",
      "toolbar_text": "rgb(66, 151, 191)",
      "frame": "rgb(142, 179, 201)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgb(66, 151, 191)",
      "tab_line": "rgba(75, 179, 228, 0.25)",
      "popup": "rgb(85, 85, 85)",
      "popup_text": "rgb(255, 255, 255)",
      "ntp_background": "rgb(102, 102, 102)",
      "tab_selected": "rgb(225, 234, 239)",
      "tab_text": "rgb(85, 85, 85)",
      "toolbar_field_border_focus": "rgba(75, 179, 228, 0.5)",
      "tab_loading": "rgba(75, 179, 228, 0.25)"
    }
  }
}