Hi,
In my issue there is no case of dimming.
I open the Find box. There is no selection right now. I click next on the find box and the text is highlighted in grey.
I haven't observed this behaviour in MS Word, Notepad, Netbeans, etc.
In notepad, the matched text is highlighted in blue while the find box is still open and the find box has the focus.
If a popup opens then you can dim the current selection.
But if the job of the popup is to highlight text then it should use some contrasting color because in most of the cases the text is black/dark. Even in dark mode, it is not necessary that the text will be in white. I have tried some dark themes in Geany but I like the default theme more than other themes.
Regards, Amit