Examine source code of Monstercat Flat Grey

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#2b2b2b",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Monstercat Flat Grey",
  "manifest_version": 2,
  "description": "Simple Monstercat theme for Firefox.\n\nI am not affiliated with Monstercat or any associated entites, I just made this for fun.\n\nImages © 2017 Monstercat.\nAll Rights Reserved."
}