Examine source code of An official looking theme

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "An official looking theme",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(13, 45, 142, 0.66)",
      "toolbar_text": "rgb(233, 175, 3)",
      "frame": "rgb(13, 45, 142)",
      "tab_background_text": "rgb(233, 175, 3)",
      "toolbar_field": "rgb(233, 175, 3)",
      "toolbar_field_text": "rgb(13, 45, 142)",
      "tab_line": "rgb(255, 162, 0)",
      "popup": "rgb(233, 175, 3)",
      "popup_text": "rgb(13, 45, 142)",
      "tab_loading": "rgb(255, 162, 0)"
    }
  }
}