This bug was fixed in the package plymouth - 0.9.4git20190712-0ubuntu4
--------------- plymouth (0.9.4git20190712-0ubuntu4) eoan; urgency=medium
* debian/plymouth-theme-spinner.postinst/rm: - call update-grub when installing/removing the theme so grub isn't stucked on colors from the old theme (lp: #1837360)
-- Sebastien Bacher <email address hidden> Wed, 09 Oct 2019 17:23:40 +0200
This bug was fixed in the package plymouth - 0.9.4git2019071 2-0ubuntu4
--------------- 12-0ubuntu4) eoan; urgency=medium
plymouth (0.9.4git201907
* debian/ plymouth- theme-spinner. postinst/ rm:
- call update-grub when installing/removing the theme so grub isn't
stucked on colors from the old theme (lp: #1837360)
-- Sebastien Bacher <email address hidden> Wed, 09 Oct 2019 17:23:40 +0200