Examine source code of Simpler dark

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Simple dark",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-036-40a272fe657f748396e017c7a64ee2dc.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(30, 30, 30, 0.8)",
      "toolbar_text": "rgb(140, 175, 200)",
      "frame": "rgb(10, 10, 10)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgba(15, 15, 15, 0.45)",
      "toolbar_field_text": "rgb(255, 92, 207)",
      "tab_line": "rgb(255, 0, 255)",
      "popup": "rgb(35, 35, 35)",
      "popup_text": "rgb(255, 255, 255)",
      "button_background_hover": "rgb(80, 80, 80)",
      "icons": "rgb(0, 175, 250)",
      "ntp_background": "rgb(45, 0, 45)",
      "tab_text": "rgb(255, 255, 255)",
      "tab_loading": "rgb(255, 0, 255)"
    }
  }
}