This was my biggest take-away from the article too. It never occurred to me to even try interacting with a CLI application with my mouse.

I'd appreciate it if more developers considered 'discoverability' as a core part of their design philosophy. I think the author is close, but when you need to ask someone/search 'why is this green?' that's enough of a barrier that most people won't bother asking (or it'll be a small enough issue that they don't consciously notice it).

There's even a generally accepted solution for explaining semantic colours, a legend. Might be nice to have one down with the F-keys.