guys I have a few questions I been searching for the answers to these can anyone help?

Looking at heaps of different pictures online, ebay of 128k's for sale, some seem to have a grey surround to the Apple logo on the front of the case, while others match the overall colour of the computer, is there any significance to this?

I understand the 128 and 512 have a 64kb ROM, was there only one version of this ROM, if there were different revisions is there any way, visual or otherwise on how to spot them?

EDIT; oh and is there any good books I should purschase, to read up on these computers, that might answer all my questions?

thank you.