Improve coloring

Improved the usage of system colors, which especially makes the app
usable with dark color themes.
15 jobs for ux-improvements in 7 minutes and 35 seconds (queued for 1 second)
Status Job ID Name Coverage
  Images
manual #46012456
allowed to fail manual
build_image_fedora
manual #46012457
allowed to fail manual
build_image_fedora_system
manual #46012458
allowed to fail manual
build_image_ubuntu
manual #46012459
allowed to fail manual
build_image_win32
manual #46012460
allowed to fail manual
build_image_win64
 
  Build
passed #46012461
linux_builtin

00:05:00

passed #46012462
linux_system

00:03:39

manual #46012468
macos allowed to fail manual
macos
passed #46012463
ubuntu_appimage

00:07:34

passed #46012464
win32_build

00:04:00

manual #46012466
windows allowed to fail manual
win32_vs_build
passed #46012465
win64_build

00:05:43

manual #46012467
windows allowed to fail manual
win64_vs_build
 
  Installer
manual #46012469
allowed to fail manual
win32_vs_installer
manual #46012470
allowed to fail manual
win64_vs_installer