Examine source code of new spring theme

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "spring theme made for fun",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right bottom"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(121, 170, 132)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(255, 255, 255)",
      "tab_background_text": "rgb(221, 230, 253)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgba(49, 62, 49, 0.8)",
      "tab_line": "rgb(180, 201, 255)",
      "popup": "rgb(148, 162, 199)",
      "popup_text": "rgb(255, 255, 255)",
      "tab_loading": "rgb(180, 201, 255)"
    }
  }
}