I have added custom resolutions on Android 4.3 virtual machine in VirtualBox (installed on Windows 7 32-bit), but I manage only to work with them if they use 16bit color depth. If I set 24bit, virtual machine doesn't boot, if I set 32bit, it shows two small screens that cover upper portion of screen.
Is there a way to solve this?
There is some explanation on this thread that sounds promising. Give it a try;
Switch android x86 screen resolution