Examine source code of Beautify Developer

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Beautify Developer",
  "author": "TaqiUlAbrar",
  "icons": {
    "32": "images/icon.png"
  },
  "description": "A sleek, dark theme matched with the Firefox Developer Edition, offering a minimalist, distraction-free interface — perfect for coding in style.",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/right-img.png",
        "images/left-img.png",
        "images/center-img.png"
      ]
    },
    "properties": {
      "color_scheme": "dark",
      "content_color_scheme": "auto",
      "additional_backgrounds_alignment": [
        "right top",
        "left top",
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat",
        "no-repeat",
        "repeat-x"
      ]
    },
    "colors": {
      "frame": "#101213",
      "frame_inactive": "#161819",
      "toolbar": "#0C161ACC",
      "toolbar_text": "#D0FFFF",
      "toolbar_field": "#31383AC5",
      "toolbar_field_text": "#D0FFFF",
      "toolbar_top_separator": "#3A414750",
      "toolbar_bottom_separator": "#3A4147CC",
      "toolbar_vertical_separator": "#3A4147CC",
      "toolbar_field_border": "#3E535A81",
      "toolbar_field_focus": "#1E272BF8",
      "toolbar_field_border_focus": "#01FFF27A",
      "toolbar_field_highlight": "#01FFF240",
      "toolbar_field_highlight_text": "#FAFFEE",
      "toolbar_field_text_focus": "#FCFFFF",
      "button_background_hover": "#35444499",
      "button_background_active": "#354444",
      "bookmark_text": "#D0FFFF",
      "icons": "#01FFF2",
      "icons_attention": "#FFD1AB",
      "ntp_text": "#D0FFFF",
      "ntp_background": "#171B1DDD",
      "ntp_card_background": "#31383AFB",
      "popup": "#1E272BF8",
      "popup_text": "#FAFFEE",
      "popup_border": "#01FFF21D",
      "popup_highlight": "#2F666A80",
      "sidebar": "#202325",
      "sidebar_text": "#B5BBBA",
      "sidebar_border": "#3E535A81",
      "sidebar_highlight": "#3E535AB0",
      "sidebar_highlight_text": "#01FFF2CC",
      "tab_text": "#01FFF2",
      "tab_line": "#01FFF2AC",
      "tab_loading": "#FFD1AB",
      "tab_selected": "#0B1E25FB",
      "tab_attention_dot": "#FFD1AB",
      "tab_background_text": "#FFFFFF",
      "tab_loading_inactive": "#FFD1AB88",
      "tab_background_separator": "#3A4147CC"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{7efafb48-ba53-4f1c-8810-79548f80f1fe}"
    }
  }
}