The ADM-3A you mentioned predated the rest and was available in amber, green or white. I remember a few of the amber ones in my middle-school library, as well

The ADM-3A you mentioned predated the rest and was available in amber, green or white. I remember a few of the amber ones in my middle-school library, as well as white. I also miss the pastel case colors. The monitor on the TRS-80 was a cannibalized black and white television. Cost was probably a big factor in using white for many of those systems.