Examine source code of Cool Grey And Black Theme

{
  "name": "Cool Grey And Black Theme",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "games-config-board-icon.png"
    },
    "colors": {
      "frame": "rgba(103, 114, 138, 1)",
      "tab_background_text": "rgba(0, 0, 0, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b60cef2b-bda0-4d6e-93c6-4d7b5786b960}"
    }
  }
}