Examine source code of Winter

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Winter",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-026-829b05416f823e170310e7c826ad1bec.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(26, 26, 26)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(0, 0, 0)",
      "tab_background_text": "rgb(192, 192, 192)",
      "toolbar_field": "rgb(24, 45, 57)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(0, 153, 255)",
      "popup": "rgb(31, 34, 61)",
      "popup_text": "rgb(215, 226, 239)",
      "icons": "rgb(0, 153, 255)",
      "tab_text": "rgb(194, 240, 255)",
      "tab_loading": "rgb(0, 153, 255)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{cd63fc9e-ec59-4b51-b3a8-fa5582705a93}"
    }
  }
}