Examine source code of On Board

{
  "theme": {
    "images": {
      "theme_frame": "9onboard-h.JPG"
    },
    "colors": {
      "frame": "#000dff",
      "tab_background_text": "#00ff11"
    }
  },
  "version": "2.0",
  "name": "On Board",
  "manifest_version": 2,
  "description": "Circuit board clip art."
}