I assume that since you know what version of the engine the games are using that you know you can get open source Z-machine engines that can probably do what you want, but you'd like to use the original engines?

The EGA palette can be changed, at least for graphics mode, and I assume for text modes too since that can be done for VGA. For VGA for example, in Norton Utilities 8 there is a tool called NCC (Norton Control Center) which lets you edit the palette, save it to a file, and then use e.g. NCC MY.PAL /SET to load those settings. You could try changing the palette entry for blue to actually be black (or one of the other available colours - see https://moddingwiki.shikadi.net/wiki/EGA_Palette for all of them).

However, sometimes when a program starts it resets the palette, this certainly seems to happen for DOS EDIT for me, so maybe this wouldn't work. Perhaps there are old TSRs out there that work around this by changing the palette every time the video mode is changed or something.

Alternatively I imagine that it wouldn't be too hard for someone with a little knowledge to disassemble the engine and change the colour, it's probably a one byte patch of the executable.

There used to be an utility for DOS that got rid of colour.
Was on old diskettes.. Mono.com or something like that.
Might have been an DOS 3.x era equivalent to MODE MONO, not sure.
That utility disabled colour in my copy of Norton Commander on a 286 w/ VGA..

Found it, I think.

Good luck! 😀

Edit:

Tempest wrote on 2022-05-30, 14:14:

Or is there a way to make the game detect my card as MDA or something like that?

Yes, maybe. ATI EGA Wonder 800 : looking for driver/utility disk

Ah SETMONO, I didn't even think of that. I wonder if that will work? The mode switching software might work too, but I'm not sure what version of the EGA Wonder I have.

Are you using the original Z-machine interpreter programs that require ANSI.SYS (or similar)? If so, they use color by default if IBM or Compaq copyright messages are found in BIOS ROM, black and white otherwise. You can override the BIOS-determined default colors with a command line parameter: /M for black and white, /W for color. Dunno why "W" for color, perhaps for Wyse PC.

ripsaw8080 wrote on 2022-06-17, 14:20:

Are you using the original Z-machine interpreter programs that require ANSI.SYS (or similar)? If so, they use color by default if IBM or Compaq copyright messages are found in BIOS ROM, black and white otherwise. You can override the BIOS-determined default colors with a command line parameter: /M for black and white, /W for color. Dunno why "W" for color, perhaps for Wyse PC.

I am using the original ones that need ANSI. I'll try that and see if it works.

It works! Thank you!