Examine source code of darkcolor

{
  "theme": {
    "images": {
      "theme_frame": "headcolorstripecopy.jpg"
    },
    "colors": {
      "frame": "#ff0000",
      "tab_background_text": "#bac"
    }
  },
  "version": "2.0",
  "name": "darkcolor",
  "manifest_version": 2,
  "description": "Color stripes with a dark background."
}