Default selection region background color is invisible

I just installed a fresh new ubuntu machine, installed emacs, and went through the tutorial. When the tutorial describes selecting text, it says "Emacs highlights the text between the cursor and the position where you typed C-<SPC>".

However, the color used to highlight the selection region (#FAFAFA) is almost the same as the default background color (#FFFFFF), and is not visible to a normal human eye.

The default color of such a basic feature (mentioned in the tutorial, just after cusor movements) should be more sensible.

ProblemType: Bug
DistroRelease: Ubuntu 21.04
Package: emacs 1:27.1+1-3ubuntu3
ProcVersionSignature: Ubuntu 5.11.0-36.40-generic 5.11.22
Uname: Linux 5.11.0-36-generic x86_64
ApportVersion: 2.20.11-0ubuntu65.3
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Fri Oct 1 09:45:38 2021
InstallationDate: Installed on 2021-09-23 (7 days ago)
InstallationMedia: Ubuntu 21.04 "Hirsute Hippo" - Release amd64 (20210420)
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=en_GB:en
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
RebootRequiredPkgs: Error: path contained symlinks.
SourcePackage: emacs
UpgradeStatus: No upgrade log present (probably fresh install)