[TASK] Improve color contrast of toggle checkboxes

To allow persons with color blindness to recognize the status
of the toggle checkboxes more easy the contrast is adjusted.

Resolves: #84881
Releases: master
Change-Id: I30aff505cdaafc3272303712d7a4eb70b53c2371
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63179


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Richard Haeser <richard@maxserv.com>
Reviewed-by: Riny van Tiggelen <info@online-gamer.nl>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Richard Haeser <richard@maxserv.com>