Examine source code of Black Feathers

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#3d3b3b",
      "tab_background_text": "#c2c2c2"
    }
  },
  "version": "2.0",
  "name": "Black Feathers",
  "manifest_version": 2,
  "description": "A modern, clean, and luxurious dark theme of jet black bird feathers, rich and sophisticated, with an unobtrusive matte texture."
}