JabRef 5.0-dev--snapshot--2019-05-20--master--21b13f3f2
Windows 10 10.0 amd64
Java 1.8.0_212

• I have tested the latest development version from http://builds.jabref.org/master/ and the problem persists

The Backgroundcolour in all the dialogs (I did not test all, but it seems so) in dark-mode is bright-white.

Steps to reproduce the behavior:

1. Open Preferences / Appereance
2. dark-mode and ok
3. restart JabRef
4. Open any Dialog