Examine source code of black&azulito

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "black&blue",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-000-5672c42860d5b06e1058dc477397f3ef.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(101, 124, 164)",
      "toolbar_text": "rgb(0, 0, 0)",
      "frame": "rgb(0, 0, 0)",
      "tab_background_text": "rgb(140, 140, 140)",
      "toolbar_field": "rgb(0, 0, 0)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(255, 0, 4)",
      "popup": "rgb(0, 0, 0)",
      "popup_text": "rgb(140, 140, 140)",
      "button_background_hover": "rgb(205, 35, 38)",
      "popup_border": "rgb(255, 0, 4)",
      "tab_selected": "rgba(156, 12, 15, 0.71)",
      "toolbar_bottom_separator": "rgb(101, 124, 164)",
      "toolbar_field_border": "rgb(101, 124, 164)",
      "toolbar_top_separator": "rgb(101, 124, 164)",
      "tab_loading": "rgb(255, 0, 4)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{2a965e53-7488-4611-b095-8ded32f81638}"
    }
  }
}