Examine source code of Black Dark transparent

{
  "name": "Black Dark transparent",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "Sans titre.png"
    },
    "colors": {
      "frame": "rgba(0, 0, 0, 0)",
      "tab_background_text": "rgba(54, 54, 54, 1)",
      "toolbar": "rgba(153, 153, 153, 0.12)",
      "bookmark_text": "rgba(130, 130, 130, 1)",
      "toolbar_field": "rgba(0, 0, 0, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{1f726f5b-8817-463f-8da2-816bad68e5fa}"
    }
  }
}