If you have created the Plug-In with Delphi and set the StyleElements property of all forms/controls to its default (all options enabled), they should inherit the chosen style.
I have fixed the issue (I think it is a Delphi issue).
Steps I took was:
1) Uncheck StyleElements-seClient
2) add a line to the FormCreate method:
TheStringGird.Color := AnEditBox.Color;