Examine source code of Dark Spring

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#5e5427",
      "tab_background_text": "#fff8e8"
    }
  },
  "version": "2.0",
  "name": "Dark Spring",
  "manifest_version": 2,
  "description": "This is purely an experiment. I'm pretty sure it looks horrible. I have no idea what I am doing."
}