I can speak about Linux and Solaris. When things go utterly, horribly wrong in those operating systems, the error messages generally appear in white or gray text on a black background (in character mode).
The Linux error messages from the kernel are sometimes written in a lighthearted manner starting with the string, ``Oops'' followed by a stack trace showing the low-level details of what actually caused the kernel panic.
In every case I've encountered (rare those have been), it has always been due to a hardware component misbehaving such as a dodgy memory module or an unrecoverable I/O error on a hard drive.
I hate to say it but the only OS I have ever used that was bulletproof (or as close as it gets) was OS/370 (now zOS).
If lives are on the line, that should be the choice.