Examine source code of Sponge Theme

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Sponge Theme",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-003-31b6bea3c78e3a19fd889b0389652a94.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(225, 181, 1)",
      "toolbar_text": "rgb(1, 42, 208)",
      "frame": "rgb(251, 201, 1)",
      "tab_background_text": "rgb(1, 42, 208)",
      "toolbar_field": "rgb(251, 201, 1)",
      "toolbar_field_text": "rgb(1, 42, 208)",
      "tab_line": "rgb(1, 42, 208)",
      "popup": "rgb(251, 201, 1)",
      "popup_text": "rgb(1, 42, 208)",
      "tab_loading": "rgb(1, 42, 208)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a0c47c43-a0cd-4468-9612-35cbbb3bc013}"
    }
  }
}