[c][grep][main.c]

grepのmain.cに色の設定がある。。defaultでそういうものもってたのか。

 126 /* The color strings used for matched text.
 127    The user can overwrite them using the deprecated
 128    environment variable GREP_COLOR or the new GREP_COLORS.  */
 129 static const char *selected_match_color = "01;31";  /* bold red */
 130 static const char *context_match_color  = "01;31";  /* bold red */
 131 
 132 /* Other colors.  Defaults look damn good.  */
 133 static const char *filename_color = "35";   /* magenta */
 134 static const char *line_num_color = "32";   /* green */
 135 static const char *byte_num_color = "32";   /* green */
 136 static const char *sep_color      = "36";   /* cyan */
 137 static const char *selected_line_color = "";    /* default color pair */
 138 static const char *context_line_color  = "";    /* default color pair */

http://core.ring.gr.jp/pub/GNU/grep/grep-2.2.tar.gz