Re: modeline face under a tty

[Richard Stallman]

    What will we do if only one mode-line color is specified?

The idea I have in mind is that the colors will ALWAYS be specified
(after face merging), in that they will never be `unspecified', but
they might be unspecified-fg or unspecified-bg.

In such cases, the way to select that combination is to reset the
terminal to the default mode, perhaps apply standout mode, then maybe
specify one color.

For instance, for foreground=unspecified-bg and background=red,
you reset to the default modes, apply standout mode, then specify
red background.

I am here making some assumptions about how the terminals work;
if those assumptions are wrong, the action would be different.