Terminal emacs colors only work with TERM=xterm-256color

Question

I\'ve found that terminal emacs does not render the correct colors unless I explicitly set TERM=xterm-256color. I use gnome-terminal, and from what I understand, TERM should

Answer 1

Terminals are a special type of device. When a process sends special byte sequences (called control sequences) to the terminal, it performs some action (like cursor positioning, change colors, etc).

You can read the ANSI terminal codes to find more detail about control sequences.

But terminals come from 70s, when hardware was limited in its capabilities, and a terminal cannot provide info about its capabilities (ie. which sequences it supports).

$TERM was used to resolve this issue - it allows programs to know what to send to the terminal to get the job done. termcap and terminfo are databases that store info about terminal capabilities for many $TERM names. If your $TERM is not in the db, you must ask an administrator to add it.

All terminal emulators inherit these limitations from old hardware terminals. So they need a properly set $TERM, and the terminfo/termcap DB MUST have data for this terminal. When a virtual terminal starts it sets the $TERM variable for you (and inside programs like bash). If $TERM is not in the terminfo/termcap you can quickly define an alias from $TERM to xterm-256color (you can find examples in the termcap file on how to do that).