Examine source code of Retro Green

{
  "theme": {
    "images": {
      "theme_frame": "retrogreensmaller.jpg"
    },
    "colors": {
      "frame": "#15ed6c",
      "tab_background_text": "#10f20c"
    }
  },
  "version": "2.0",
  "name": "Retro Green",
  "manifest_version": 2,
  "description": "Green squares and at the bottom green stripes! Great for green lovers!"
}