I'm seeing a problem with basically ALL JetBrains IDE-based apps (EAP 2019.3): AppCode, DataGrip, PyCharm, CLion, IntelliJ, etc. The OS file dialogs present with the JetBrains-added portion showing light-text-on-dark, while the rest of the dialog is 10.13.6-normal "dark-on-light" color, which renders ALL text in the OS dialog unreadable (though colored icons appear fine).
Digging into it further GUI-wise, it appears that for whatever reason, the IDE is presuming that even older macOSes can support "Dark Mode" and thus changing it's palette accordingly for the dialog -- which'd be great, but 10.13 (and prior) DON'T support "Dark Mode" and for them the dialogs' text (file names, properties, etc) all appear as white-on-white, unreadable. Screen capture of problem attached:
MacPro5,1 (Mid-2012) 2x 2.4GHz 12c/24t; macOS 10.13.6; 32GB RAM