this also caught my attention. the author also questions why the screens are blue
I think he has just forgotten that in the late 90s, these color choices were entirely obvious and followed the Windows design precedent, which is why he probably didn't think much about it at the time
Indeed. For example, Windows 95's My Computer icon might have had a teal background to match the default desktop background, but the screen of the peer computer in the Network Neighborhood icon was blue.
Do you remember Microsoft Word’s “Jerry Pournelle mode”? He convinced them to ship a feature that forced Word to render white text on a blue background, just like his favourite word processor, so that he would switch. I think the last version with this feature was Word 2003.
I think he has just forgotten that in the late 90s, these color choices were entirely obvious and followed the Windows design precedent, which is why he probably didn't think much about it at the time