Examine source code of Brick red

{
  "manifest_version": 2,
  "name": "Terracotta",
  "version": "1.1",
  "theme": {
    "colors": {
      "bookmark_text": "hsla(0, 0%, 100%, 1)",
      "frame": "hsla(10, 89%, 18%, 1)",
      "frame_inactive": "hsla(10, 89%, 18%, 1)",
      "icons": "hsla(0, 0%, 100%, 1)",
      "icons_attention": "hsla(10, 87%, 90%, 1)",
      "ntp_background": "hsla(7, 97%, 1%, 1)",
      "ntp_card_background": "hsla(10, 95%, 10%, 1)",
      "ntp_text": "hsla(0, 0%, 100%, 1)",
      "popup": "hsla(10, 95%, 10%, 1)",
      "popup_border": "hsla(10, 60%, 68%, 1)",
      "popup_highlight": "hsla(10, 85%, 36%, 0.3)",
      "popup_highlight_text": "hsla(0, 0%, 100%, 1)",
      "popup_text": "hsla(0, 0%, 100%, 1)",
      "sidebar": "hsla(10, 95%, 10%, 1)",
      "sidebar_highlight": "hsla(10, 85%, 36%, 0.3)",
      "sidebar_highlight_text": "hsla(0, 0%, 100%, 1)",
      "sidebar_text": "hsla(0, 0%, 100%, 1)",
      "tab_background_text": "hsla(0, 0%, 100%, 1)",
      "tab_line": "hsla(10, 92%, 89%, 1)",
      "tab_loading": "hsla(10, 87%, 90%, 1)",
      "tab_loading_inactive": "hsla(10, 87%, 90%, 1)",
      "tab_selected": "hsla(10, 95%, 10%, 1)",
      "tab_text": "hsla(0, 0%, 100%, 1)",
      "toolbar": "hsla(11, 87%, 32%, 1)",
      "toolbar_bottom_separator": "hsla(10, 89%, 18%, 1)",
      "toolbar_field": "hsla(10, 89%, 18%, 1)",
      "toolbar_field_border": "hsla(10, 60%, 68%, 1)",
      "toolbar_field_focus": "hsla(10, 95%, 10%, 1)",
      "toolbar_field_text": "hsla(0, 0%, 100%, 1)",
      "toolbar_text": "hsla(0, 0%, 100%, 1)",
      "toolbar_field_text_focus": "hsla(0, 0%, 100%, 1)",
      "toolbar_field_highlight_text": "hsla(0, 0%, 100%, 1)",
      "toolbar_top_separator": "hsla(10, 60%, 68%, 1)",
      "panel_separator": "hsla(10, 60%, 68%, 1)"
    },
    "properties": {
      "color_scheme": "dark",
      "content_color_scheme": "dark"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{25b5a343-4238-4bae-b1f9-93a33f258167}"
    }
  }
}