Examine source code of Shiny squares

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#f0f088",
      "tab_background_text": "#b1e0ac"
    }
  },
  "version": "2.0",
  "name": "Shiny squares",
  "manifest_version": 2,
  "description": "First try"
}