Examine source code of Dirty Canvas 2

{
  "theme": {
    "images": {
      "theme_frame": "header1.jpg"
    },
    "colors": {
      "frame": "#383535",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Dirty Canvas 2",
  "manifest_version": 2,
  "description": "Give your browser that rustic artistic look with this awesome canvas theme. Simplistic design allows for easy reading and also looks cool."
}