you're annoyed by the color

I'm annoyed that the colorisation doesn't repect my existing setup.

If they changed the foreground color leaving my existing background intact (subject to no white-on-white scenario), I would probably have said "That's cool!" and used it.

I might have even lived with them changing the background color, so long as they set the background color of the entire screen so you don't end up with this red or green on black in a sea of white, which is completely unreadable. (Well, maybe!)

I'm annoyed that when you quit, they do not restore my originals setting. This is trivial to implement.

I'm annoyed that there is no simple way to turn it off.

I'm annoyed that this experimental feature is on by default, rather than opt-in.

having to press Ctrl-C

Hitting ^C isn't enough. Because they don't restore the original settings, once you've left cpan, you have to reset your colors and clear the screen before you can read what you've typed.

Complicated further by the fact that I use different colors for different types of session--32-bit perl; 64-bit perl; 32-bit compiler; 64-bit compiler; debug builds; release builds. once they've messed with things, I then have to remember what the appropriate values are to restore them. Or throw away the session along with any information buffered on the screen amd in the session history buffers and start a new one.

and not by ..., setup your compiler and relaunch cpan?

I'm not quite sure why you think that doesn't annoy me? The sentence preceding the one you've quoted is a fairly strong indication that I'm not too happy about that either.

In the end, the provision of a simple color [on|off] command (with the default off!), would be just so easy to implement and far better than the current 10 steps. (Which don't even work!)