Examine source code of Dark Within Temptation

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#ffffff",
      "tab_background_text": "#c4c4c4"
    }
  },
  "version": "2.0",
  "name": "Dark Within Temptation",
  "manifest_version": 2,
  "description": "This is a dark theme of the band Within Temptation. I have made the letters smaller so it fits on every screen and don't need a big addon bar."
}