`xterm-color' might activate the color support on an xterm-compatible
emulator.
-Beginning with version 21.3, Emacs supports the --color command-line
+Beginning with version 21.4, Emacs supports the --color command-line
option which may be used to force Emacs to use one of a few popular
modes for getting colors on a tty. For example, --color=ansi8 sets up
for using the ANSI-standard escape sequences that support 8 colors.