Examine source code of Focus Before Spring

{
  "theme": {
    "images": {
      "theme_frame": "top8.jpg"
    },
    "colors": {
      "frame": "#cfc0c0",
      "tab_background_text": "#fcfcfc"
    }
  },
  "version": "2.0",
  "name": "Focus Before Spring",
  "manifest_version": 2,
  "description": "Part of the Focus Series, 12 grades of colour for 12 hours a day."
}