Precompiled header files in VS2019

[John E]

If I select my project's properties in VS2019 and I click Configuration Properties->C/C++->Precompiled Headers I can see that it's set to Not Using Precompiled Headers. And yet If I try to compile a project, every source file seems to generate a file with the extension .ipch - for example, test.cpp would generate test.ipch

Are these files anything to do with precompiled headers? Typically they're around 130MB size so I'd prefer not to generate them if I can avoid them.

[John E]

It turned out that these are somehow connected to Intellisense but they can be switched off if you're prepared to dig deep enough:-

Tools->Options->Text Editor->C/C++->Advanced->Intellisense->Disable Automatic Precompiled Header

which brings up another question... in earlier versions of VS, Intellisense would draw irrelevant stuff grayed out - whereas it now prints those items in their normal colour (but slightly dimmed). I preferred the grayed out method. Is it possible to get back to that mode? I found loads of options in the above Intellisense menu but I couldn't find a colour setting there