duckjun,
Thank you for the screenshot. I could replicate the issue with white background at my end. I see the same problem with Eclipse’s Dark theme as well which might be an Eclipse issue and not DevStyle’s. I will check with the dev team if we can work on it and file a bug accordingly.
As a workaround, please set the background color manually here : Window > Preferences > PyDev > Interactive Console to a color of your choice.
Apologies for inconvenience caused. Please let us know if you have any further questions.
–Swapna
Genuitec Support