Flat Dark theme renders black text on dark gray background in SCXML editor attributes view

Steps to reproduce the issue

1. Change QtCreator theme to Flat Dark
2. Enable SCXMLEditor Qt Creator plugin
3. Create new SCXML file and open it in editor

Expected outcome:
Colors used in SCXML editor attributes view have enough contrast for proper readability

Actual outcome:
Colors used in SCXML editor attributes view are too close to each other making the reading difficult