Examine source code of Black Gray n Blue

{
  "name": "Black Gray n Blue",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "Screenshot_2019-06-10 Theme generate Developer Hub Add-ons for Firefox.png"
    },
    "colors": {
      "frame": "rgba(5, 5, 5, 1)",
      "tab_background_text": "rgba(200, 200, 200, 1)",
      "toolbar": "rgba(25, 25, 25, 1)",
      "bookmark_text": "rgba(0, 80, 240, 1)",
      "toolbar_field": "rgba(5, 5, 5, 1)",
      "toolbar_field_text": "rgba(250, 250, 250, 1)"
    }
  }
}