Examine source code of RednBlack

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "RednBlack",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-000-5672c42860d5b06e1058dc477397f3ef.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(18, 18, 18)",
      "toolbar_text": "rgb(255, 5, 21)",
      "frame": "rgb(16, 16, 16)",
      "tab_background_text": "rgb(255, 5, 21)",
      "toolbar_field": "rgb(16, 16, 16)",
      "toolbar_field_text": "rgb(255, 5, 21)",
      "tab_line": "rgb(255, 5, 21)",
      "popup": "rgb(19, 19, 19)",
      "popup_text": "rgb(255, 5, 21)",
      "button_background_hover": "rgb(14, 14, 14)",
      "popup_border": "rgb(0, 0, 0)",
      "sidebar_border": "rgb(0, 0, 0)",
      "sidebar_text": "rgb(255, 5, 21)",
      "sidebar": "rgb(18, 18, 18)",
      "tab_background_separator": "rgb(0, 0, 0)",
      "toolbar_bottom_separator": "rgb(0, 0, 0)",
      "toolbar_field_border_focus": "rgb(255, 5, 21)",
      "toolbar_field_border": "rgb(0, 0, 0)",
      "toolbar_field_highlight": "rgba(255, 0, 0, 0.37)",
      "toolbar_field_separator": "rgb(0, 0, 0)",
      "toolbar_top_separator": "rgb(0, 0, 0)",
      "toolbar_vertical_separator": "rgb(0, 0, 0)",
      "tab_loading": "rgb(255, 5, 21)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{df97ed6f-03fe-4497-9e6d-4b4a4090cdaf}"
    }
  }
}