Colour abnormalities in ReactOS under VirtualBox with VBGA

[fusion809]

Hi,

With VirtualBox Guest Additions (VBGA) installed in my ReactOS 0.4.4 guest OS (i.e., I'm running ReactOS IN VirtualBox with my host operating system being Funtoo Linux, if it is somehow relevant) I'm getting this bizarre colour issue...



Before installing VBGA the colours were normal but the screen was rather small (like 800x600 when my laptop's resolutions are 1600x900). I installed ReactOS following the Wiki article https://reactos.org/wiki/VirtualBox. That is:

* I downloaded the 0.4.4 ReactOS ISO, not the LiveCD one as I had problems running the installer in the LiveCD ISO.
* I set the OS type to Windows 2003 (32-bit)
* I allocated 4 GB RAM to the VM (my laptop has 16 GB RAM total).
* I allocated a single CPU core the VM (with 8 CPU cores in my laptop)
* Added a disk image for the VM's hard drive. It's size is 128 GB (granted I doubt this is relevant, but still I did set a big heap of drive space to it!)
* Had an empty optical disk (although I since inserted the VBGA disk image into this empty disk space)
* Unchecked 'Enable I/O APIC'
* Set the network to 'PCnet-FAST III' (and despite this choice I still get asked to install network drivers when I boot the ReactOS system the first time after installation and configuration is finished. Clicking next on this window causes it to give me a message saying the installation failed)
* Started the VM and went through the installation process.
* Rebooted and went through the configuration process (setting my username, admin password, etc.)
* Rebooted and started ReactOS.
* Inserted the VBGA disk
* Opened the D:// optical drive (wherein the VBGA disk was) in "My Computer" and double-clicked the x86 exe installater, went through the installer and rebooted after.
* Opened my E:// drive and ran the Setup.exe installer for Outlive.

then these visual changes became as obvious as they are in the above screenshot.

My VirtualBox version is 5.1.18 if relevant.

[fusion809]

Per gigahertz's answer in the #reactos IRC channel I merely had to go to Control Panel -> Display and go to settings and set the "Colors" to "True Color (32 Bit)".

[EmuandCo]

Things will look better in next version, but 32 bit is the way to go, yes ^^

[PurpleGurl]

Yes, that is the type of effect you get when there aren't enough colors. I'm surprised it dithers as good as it did. 16-24 bit also might work if that's available, but there'd likely be more banding. That tends to happen more in movies.

As a side note, I remember reading something counter-intuitive. It seems like 16-bit video could be faster in some situations, but since it is a 32-bit OS, 32-bit could be faster.

[mauro451]

I have solved this by selecting (Vbox guest session menu entries); "fit guest screen mode" , otherwise screen resolution in ROS settings could not get into 32 bit mode with the optimal size. Of course you should have applied Guest Addition before