Overview
Unfortunately jeos-firstboot currently uses --palette vga so that would break it: https://github.com/openSUSE/jeos-firstboot/blob/fafe62d0d46809688e064ca92d49ccbe64f833ed/files/usr/sbin/jeos-firstboot#L125
It's currently not used in any image (I think), but would be nice to have an alternative.
This /etc/kmscon/kmscon.conf should get you started.
font-name=Mx437 IBM VGA 9x16 font-size=24 palette=custom palette-foreground=170,170,170 palette-red=170,0,0 palette-green=0,170,0 palette-yellow=170,85,0 palette-blue=0,0,170 palette-magenta=170,0,170 palette-cyan=0,170,170 palette-light-grey=170,170,170 palette-dark-grey=85,85,85 palette-light-red=255,85,85 palette-light-green=85,255,85 palette-light-yellow=255,255,85 palette-light-cyan=85,255,255
Does it support /usr/etc or similar as well? Otherwise we can't ship that in an rpm. Passing that as parameters in jeos-firstboot might work though, but look odd...
Not out of the box; we'd have to patch it to make use of libeconf. Or we could just patch kmscon to default to VGA colors. I'd personally like that, too. I never understood why xterm, gnome-terminal, name any terminal, always have to come up with their own debatable styles.
Yes, that's what I'd prefer as well, especially because kmscon is meant to be a replacement for the linux fbcon. It would be incompatible with upstream unfortunately.
For the time being we could also just keep 0001-Add-new-palette-with-standard-VGA-colors.patch as a compromise
