Examine source code of Treehouse - black ice

{
  "theme": {
    "images": {
      "theme_frame": "Treehouse_top1.jpg"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Treehouse - black ice",
  "manifest_version": 2,
  "description": "Treehouse boardgame pieces - picture used with kind permission from John \n(BGG account peapicker)"
}