Examine source code of Cool Branches

{
  "theme": {
    "images": {
      "theme_frame": "Abstrakt5.jpg"
    },
    "colors": {
      "frame": "#162b69",
      "tab_background_text": "#f3851a"
    }
  },
  "version": "2.0",
  "name": "Cool Branches",
  "manifest_version": 2,
  "description": "I tried inversing the colors of an image with some trees and got the idea to turn the hue back to blue. I did some tweaking, but that's basicly it. :)"
}