same for me i'm on a HP Elitebook 2460p

Try to change the System Language to English and Use your graphics card driver.

I've changed it to English. That's why i wrote
And the only available driver is the default, open source driver.

Here's two more. The one with the strange-coloured screen has occured when I tried to change the color temperature of my screen using xflux. The other is what i get after running sudo /sbin/vboxconfig on GUI. I didn't triy to do that it in console. Instead of that, I just booted with rw init=/bin/bash and run it from there. No error this time, except for a few 'No such file or directory'. Rebooted normally and VirtualBox is now working. Also I didn't install VirtualBox from Deepin's repository. I've installed it from a .deb file, downloaded from VirtualBox's website.

Same for me on Deepin 15.4 virtualized in VirtualBox with Guest Additions installed manually.
Intel integrated GPU, i5 7th generation CPU. Latest version of VirtualBox and Guest Additions.
No problem with Debian when I use Guest Additions.

Deepin 15.3 doesn't install anymore for me (that's another story), so I use Deepin 15.4 for everyday usage (beside Windows 8.1 for gaming). So unfortunately this is not just a VM.

I have the same issues