Examine source code of Black Abstract Theme

{
  "name": "black-background-sand-0lrg7eosq116z7dt",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "dark-abstract-black-minimal-4k-q0-3840x2160.jpg"
    },
    "colors": {
      "frame": "rgba(229, 230, 232, 1)",
      "tab_background_text": "rgba(212, 212, 212, 1)",
      "toolbar": "rgba(61, 61, 61, 1)",
      "bookmark_text": "rgba(209, 209, 209, 1)",
      "toolbar_field": "rgba(217, 217, 217, 1)",
      "toolbar_field_text": "rgba(0, 0, 0, 1)",
      "tab_line": "rgba(255, 255, 255, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d453d81c-5f10-444b-bfaf-0ab7e9b7e53a}"
    }
  }
}