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I am preparing for the CompTIA Server+ exam and was going through their official practice questions. I came across a confusing question.

Question 10

An administrator is unable to access a Linux host running virtual servers. Upon further investigation, the administrator views the console of the server and determines the server has crashed. Which of the following is the color of the screen?

A. White B. Black C. Green D. Purple E. Blue

I confidently chose "B. Black", since I thought the administrator switched to a virtual terminal with Ctrl+Alt+F3 to switch to CLI mode and check logs. Since terminals are black, I thought that would be the answer. I also came up with Kernel Panics, which are also displayed on the black screen as text. To my surprise, the answer was "D, Purple".

This isn't Windows so the screen shouldn't turn blue or any other color when something fatal happens. Am I missing something?

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    I mostly run headless servers (I.e. command line, no GUI; monitor/keyboard can be attached if necessary). In 20+ years I can confidently say I have never seen a crashed system with a purple screen. Black background with white text is the usual for a console Commented Sep 28 at 15:52
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    is it about the drm/panic blue screen? or some oddity of a given virtualization solution... or IPS glow that makes black appear kinda purple on some monitors Commented Sep 28 at 15:58
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    Was this question geared at a particular OS? ESXi goes purple; and Ubuntu can get stuck on boot which then leaves you w/ an all purple console. But the question is poorly worded/inaccurate. Commented Sep 28 at 16:27
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    ESXi has nothing to do with Linux, though, so describing an ESXi host as a "Linux host" is just plain wrong. Commented Sep 29 at 16:08
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    If this were a real question in a real exam I'd challenge it. In this context it just diminishes the value of test questions and the supplier/author. And if this is the quality of the exam, it reduces my perceived value of the qualification and thus any applicant who earned it. Commented Sep 30 at 0:42

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To me, a server displaying a purple screen is a crashed ESX host. I’m not aware of any Linux-based system showing a purple screen when crashed.

ESX used to include a Linux kernel for its first (service) VM, but that’s not been the case for a while. So the mention of virtual servers in the question could suggest ESX, but not the mention of Linux…

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I confidently chose "B. Black", since I thought the administrator switched to a virtual terminal with Ctrl+Alt+F3 to switch to CLI mode and check logs. Since terminals are black, I thought that would be the answer. I also came up with Kernel Panics, which are also displayed on the black screen as text. To my surprise, the answer was "D, Purple".

My first guess is that someone wrote this question based on drm_panic demos. Linux's DRM graphics subsystem has recently gotten a kernel panic handler, so that the kernel could automatically switch from graphics mode upon kernel panic (at which point manual virtual-console switching would no longer work). The default CONFIG_DRM_PANIC_BACKGROUND_COLOR is black, but one of the demonstration screenshots had purple. I wouldn't be surprised if e.g. Ubuntu chose some shade of "Canonical™ Purple" in its kernel builds.

My second guess is that (again) Ubuntu previously had some kind of (Plymouth-based?) crash screen. Sorry, I don't have anything definite.

This isn't Windows so the screen shouldn't turn blue or any other color when something fatal happens. Am I missing something?

Blue is not exclusive to Windows. Any other OS can implement a blue crash screen (indeed systemd now ships a systemd-bsod which uses blue). I recall OpenBSD uses white-on-blue for its kernel console output. Whereas Windows 11 now uses a black crash screen.

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    Windows also has a green screen on insider builds (which my machine, despite not being and never having been an insider build, managed to do at one point!). Commented Oct 1 at 12:47
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    @Bob Windows 3.1 even had windows.ini settings for the colours Commented Oct 1 at 13:18

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