bug#64740: 28.2; screen interacts badly with TERMCOLOR=truecolor

[Francesco Potortì]

>> emacs -nw -Q  behaves strangely under Screen when COLORTERM=truecolor
>> 
>> If I unset COLORTERM  the problem goes away
>> 
>> The problem does not happen outside of Screen.
>> 
>> The problem is that Emacs starts as if it could not use the terminal's 
>> reverse capability, that is, the mode line is made of hyphens rather than 
>> filled characters.  Also, all text is dimmed.  Moreover, the text stays 
>> dimmed in the shell after exiting Emacs.
>> 
>> I do not know if this is an Emacs problem, a Screen problem or else, and 
>> unfortunately at the moment I have no time to dig deeper, hope someone else 
>> can.
>
>It's a Screen problem, see etc/PROBLEMS and bug#62237.  Since you only
>have Emacs 28, I reproduce the PROBLEMS entry below:

>  ** Colors are not available or messed up on TTY frames inside 'screen'.
...
>  The solution is to either upgrade to a newer version of 'screen'
>  (version 5.x or later reportedly supports true color), or to unset the
>  COLORTERM variable before starting 'screen'

Thank you Eli.  In fact, I am on Debian testing which sports Screen 4.9.0.  
Don't know why this bag has started affecting me only now.

Sorry for the duplicate