Examine source code of Energy Transition

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#dbccff",
      "tab_background_text": "#2e4004"
    }
  },
  "version": "2.0",
  "name": "Energy Transition",
  "manifest_version": 2,
  "description": "Transition from bright purple to blue in header, blue skies in footer.\n\nThe footer isn't very interesting, so it'll work best with a low height."
}