RE: defined-colors doc string doesn't describe nil FRAME

[Drew Adams]

    > OK. So, IIUC, a library that is not going to be used on a tty
    > might have an interest in caching (defined-colors) in its own defconst
    > variable. Correct?

    Maybe (assuming I didn't miss anything in my description).

    But how would you know that a library is not going to be used on a
    tty?

It requires frames.

    Also, is the call to defined-colors really that expensive?  I just
    tried it, and the response was immediate.

I call it quite often (although I do use a `let' to avoid multiple calls in
the same function). Rather, I call it in user commands that are on
repeatable keys, so they are often executed in succession, with the same
call to `defined-colors', producing the same list of colors.