Index: usr.bin/grep/grep.h
===================================================================
--- usr.bin/grep/grep.h
+++ usr.bin/grep/grep.h
@@ -51,6 +51,10 @@
 
 #define	VERSION		"2.5.1-FreeBSD"
 
+#define COLOR_NONE 0
+#define COLOR_AUTO 1
+#define COLOR_ALWAYS 2
+
 #define	GREP_FIXED	0
 #define	GREP_BASIC	1
 #define	GREP_EXTENDED	2
@@ -118,7 +122,7 @@
 extern long long mlimit;
 extern char	*label;
 extern const char *color;
-extern int	 binbehave, devbehave, dirbehave, filebehave, grepbehave, linkbehave;
+extern int	 binbehave, colorbehave, devbehave, dirbehave, filebehave, grepbehave, linkbehave;
 
 extern bool	 file_err, first, matchall, prev;
 extern int	 tail;
Index: usr.bin/grep/grep.c
===================================================================
--- usr.bin/grep/grep.c
+++ usr.bin/grep/grep.c
@@ -120,6 +120,7 @@
 bool	 nullflag;	/* --null */
 char	*label;		/* --label */
 const char *color;	/* --color */
+int  colorbehave = COLOR_NONE;	/* --color=when: when to color */
 int	 grepbehave = GREP_BASIC;	/* -EFGP: type of the regex */
 int	 binbehave = BINFILE_BIN;	/* -aIU: handling of binary files */
 int	 filebehave = FILE_STDIO;	/* -JZ: normal, gzip or bzip2 file */
@@ -620,12 +621,15 @@
 
 				term = getenv("TERM");
 				if (isatty(STDOUT_FILENO) && term != NULL &&
-				    strcasecmp(term, "dumb") != 0)
+				    strcasecmp(term, "dumb") != 0) {
 					color = init_color("01;31");
+					colorbehave = COLOR_AUTO;
+				}
 			} else if (strcasecmp("always", optarg) == 0 ||
 			    strcasecmp("yes", optarg) == 0 ||
 			    strcasecmp("force", optarg) == 0) {
 				color = init_color("01;31");
+				colorbehave = COLOR_ALWAYS;
 			} else if (strcasecmp("never", optarg) != 0 &&
 			    strcasecmp("none", optarg) != 0 &&
 			    strcasecmp("no", optarg) != 0)
Index: usr.bin/grep/util.c
===================================================================
--- usr.bin/grep/util.c
+++ usr.bin/grep/util.c
@@ -443,6 +443,7 @@
 {
 	size_t a = 0;
 	int i, n = 0;
+	bool docolor = false;
 
 	if (!hflag) {
 		if (!nullflag) {
@@ -470,16 +471,20 @@
 	/* --color and -o */
 	if ((oflag || color) && m > 0) {
 		for (i = 0; i < m; i++) {
+			if(color && (colorbehave == COLOR_ALWAYS ||
+			    (!oflag && (matches[i].rm_so != 0 || (size_t)matches[i].rm_eo != line->len))))
+				docolor = true;
+
 			if (!oflag)
 				fwrite(line->dat + a, matches[i].rm_so - a, 1,
 				    stdout);
-			if (color) 
+			if (docolor)
 				fprintf(stdout, "\33[%sm\33[K", color);
 
 				fwrite(line->dat + matches[i].rm_so, 
 				    matches[i].rm_eo - matches[i].rm_so, 1,
 				    stdout);
-			if (color) 
+			if (docolor)
 				fprintf(stdout, "\33[m\33[K");
 			a = matches[i].rm_eo;
 			if (oflag)