Examine source code of longhorn aurora

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "longhorn aurora",
  "description": "aurora longhorn animated with apng",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/longhorn.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "left"
      ],
      "additional_backgrounds_tiling": [
        "repeat-x"
      ]
    },
    "colors": {
      "toolbar": "rgba(197, 211, 216, 0.25)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgba(255, 255, 255, 0.01)",
      "tab_background_text": "rgb(0, 15, 1)",
      "toolbar_field": "rgba(255, 255, 255, 30)",
      "toolbar_field_text": "rgb(0, 15, 1)",
      "tab_line": "rgb(232, 30, 167)",
      "popup": "rgb(255, 255, 255)",
      "popup_text": "rgb(0, 15, 1)",
      "tab_loading": "rgb(255, 255, 255)"
    }
  }
}