I know that we can change the color of selected text but only if the window is active.
When the window is inactive the color of the selection will change (depending on the theme in windows I think) to gray.
In Windows Notepad the color of the selection will not change. Here is a screenshot where both Notepad and ScintillaNET windows are inactive:
Is it possible to keep the selection color in ScintillaNET while the window is inactive?