The Mac II Portrait Video Card supports 2-bit (4 grays) graphics on the Apple Portrait (640 X 870) Monitor.  It will not work with the Apple Multiple Scan 20 Display even when that display is set to 640 X 870 mode.

The Mac II Portrait Video Card can be upgraded with eight Mac II Video Expansion RAM Chips so that it is capable of supporting 4-bit (16 grays) video.