He says he doesn't remember why he picked blue for the screen, but that was a standard color for screens depicted in Win 3.x and Win95 icons, so I would assume he was just following that.
Also, you are right indeed. I remember Windows 3.1, 95, 98, etc. used blue as the screen colour for icons depicting computers. For icons that had two computers (e.g. "Network Neighborhood"), one computer had blue screen and the other one had cyan.
Colour 15, on the other hand, is typically called "bright white" or "high-intensity white", which is indeed too saturated. When I said "white," I was referring to colour 7, not colour 15.
For reference, here's the palette I'm referring to: https://moddingwiki.shikadi.net/wiki/EGA_Palette
Additionally, here are examples from printed materials of that era confirming these colour names:
1) https://archive.org/download/logo-programming-with-turtle-gr... - Page 6-3 refers to colour 7 as white and colour 15 as high-intensity white.
2) https://bitsavers.computerhistory.org/pdf/microsoft/gw-basic... - Page 289 refers to colour 7 as white and colour 15 as high-intensity white.
My roommate sweet talked the housing people into letting us have a second land line (ethernet was still being piloted in a different dorm) so we could log in from our room. It’s a wonder that I was surprised when he ended up in management.
I had to zoom in to verify that it's not the same.