Examine source code of retro style2

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "retro2",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right bottom"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(105, 221, 105, 0.15)",
      "toolbar_text": "rgb(10, 11, 10)",
      "frame": "rgb(253, 149, 212)",
      "tab_background_text": "rgb(227, 241, 245)",
      "toolbar_field": "rgba(255, 255, 255, 0)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(194, 194, 194)",
      "popup": "rgba(79, 122, 76, 0.51)",
      "popup_text": "rgb(255, 255, 255)",
      "tab_loading": "rgb(194, 194, 194)"
    }
  }
}