Not really. I think it comes from shell-mode. In Apple Terminal it looks like this:
.emacs:503: '(comint-prompt-regexp "^[a-z]+ [0-9]+ /\\\\ " t)
.emacs:620: '(shell-prompt-pattern "^[a-z0-9]+ [0-9]+ /\\\\ ")
.emacs:650: '(comint-highlight-prompt ((t (:background "khaki" :foreground "firebrick" :weight bold))))
.emacs:670: '(minibuffer-prompt ((t (:background "yellow" :foreground "dark red" :weight bold))))
Yes. It's defined like this in ~/.tcshrc:
11 if ($?TERM) then
12 if (($TERM == xterm) | ($TERM == nxterm)) then
13 setenv TERM xterm-color
17 endif
43 if (($TERM == eterm-color) | ($TERM == xterm-256color) | ($TERM == xterm-color)) then
44 set red="%{\033[1;47;31m%}"
45 set green="%{\033[0;47;32m%}"
46 set yellow="%{\033[1;33m%}"
47 set blue="%{\033[1;34m%}"
48 set magenta="%{\033[1;35m%}"
49 set cyan="%{\033[1;36m%}"
50 set white="%{\033[0;37m%}"
51 set end="%{\033[0m%}" # This is needed at the end... :(
52 # set prompt = "`echo \e[31\;47\;1m\j-$user` ! /\\ "
53 set prompt="${red}%n ! /\\ ${end} "
54 # set prompt="${red}%n${blue}@%m ${white}%~ ${green}! /\\ ${end}"
55 # set prompt="[${green}%n${blue}@%m ${white}%~ ]${end}"
56 unset red green yellow blue magenta cyan yellow white end
57 else
58 set prompt = "`echo $user` ! /\\ "
59 endif
126 endif