Examine source code of Dark Red simple theme

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Red",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg",
        "images/1.jpg",
        "images/2.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "left top",
        "right top",
        "center top"
      ],
      "additional_backgrounds_tiling": [
        "repeat",
        "repeat",
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(43, 43, 48)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(255, 255, 255)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(72, 12, 3)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(195, 229, 26)",
      "popup": "rgb(43, 43, 48)",
      "popup_text": "rgb(255, 255, 255)",
      "button_background_hover": "rgba(180, 180, 183, 0.83)",
      "icons": "rgb(255, 255, 255)",
      "tab_loading": "rgb(195, 229, 26)"
    }
  }
}