Someone decided to put together a parts list and 3D printer files for a compact Mac based on a Raspberry Pi and Mini vMac:

https://learn.adafruit.com/mini-mac-pi/



While the resolution of the screen is only 320x240, it scrolls so it can support a higher resolution. The screen is color and the emulation can support color, too. Sound and networking isn't working yet, but people can get that working with a little effort.