Examine source code of TetorisV1.3

{
  "name": "TetorisV1.3",
  "manifest_version": 2,
  "version": "3.0",
  "theme": {
    "images": {
      "theme_frame": "tetoris3-ezgif.com-gif-to-apng-converter.png"
    },
    "colors": {
      "frame": "rgba(249, 222, 87, 1)",
      "tab_background_text": "rgba(0, 0, 0, 1)",
      "toolbar": "rgba(0, 0, 0, 0)",
      "bookmark_text": "rgba(0, 0, 0, 1)",
      "toolbar_field": "rgba(0, 0, 0, 0)",
      "toolbar_field_text": "rgba(0, 0, 0, 1)",
      "tab_line": "rgba(0, 0, 0, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{56f7ea8e-890b-4557-9064-2e29edc58baf}"
    }
  }
}