diff --git a/builtin/branch.c b/builtin/branch.c
index b15fee5e31..d6d3c7d85b 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -88,7 +88,7 @@ static int git_branch_config(const char *var, const char *value, void *cb)
 
 static const char *branch_get_color(enum color_branch ix)
 {
-	if (branch_use_color > 0)
+	if (want_color(branch_use_color))
 		return branch_colors[ix];
 	return "";
 }
diff --git a/builtin/config.c b/builtin/config.c
index 5505ced8c1..3a092966d2 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -330,6 +330,8 @@ static int get_colorbool(int print)
 			get_colorbool_found = git_use_color_default;
 	}
 
+	get_colorbool_found = want_color(get_colorbool_found);
+
 	if (print) {
 		printf("%s\n", get_colorbool_found ? "true" : "false");
 		return 0;
diff --git a/builtin/show-branch.c b/builtin/show-branch.c
index e6650b4837..4b726fabde 100644
--- a/builtin/show-branch.c
+++ b/builtin/show-branch.c
@@ -26,14 +26,14 @@ static const char **default_arg;
 
 static const char *get_color_code(int idx)
 {
-	if (showbranch_use_color)
+	if (want_color(showbranch_use_color))
 		return column_colors_ansi[idx % column_colors_ansi_max];
 	return "";
 }
 
 static const char *get_color_reset_code(void)
 {
-	if (showbranch_use_color)
+	if (want_color(showbranch_use_color))
 		return GIT_COLOR_RESET;
 	return "";
 }
diff --git a/color.c b/color.c
index 67affa4765..85864176a6 100644
--- a/color.c
+++ b/color.c
@@ -166,7 +166,7 @@ int git_config_colorbool(const char *var, const char *value)
 		if (!strcasecmp(value, "always"))
 			return 1;
 		if (!strcasecmp(value, "auto"))
-			goto auto_color;
+			return GIT_COLOR_AUTO;
 	}
 
 	if (!var)
@@ -177,7 +177,11 @@ int git_config_colorbool(const char *var, const char *value)
 		return 0;
 
 	/* any normal truth value defaults to 'auto' */
- auto_color:
+	return GIT_COLOR_AUTO;
+}
+
+static int check_auto_color(void)
+{
 	if (color_stdout_is_tty < 0)
 		color_stdout_is_tty = isatty(1);
 	if (color_stdout_is_tty || (pager_in_use() && pager_use_color)) {
@@ -188,6 +192,18 @@ int git_config_colorbool(const char *var, const char *value)
 	return 0;
 }
 
+int want_color(int var)
+{
+	static int want_auto = -1;
+
+	if (var == GIT_COLOR_AUTO) {
+		if (want_auto < 0)
+			want_auto = check_auto_color();
+		return want_auto;
+	}
+	return var > 0;
+}
+
 int git_color_default_config(const char *var, const char *value, void *cb)
 {
 	if (!strcmp(var, "color.ui")) {
diff --git a/color.h b/color.h
index a190a2522b..b413e0eace 100644
--- a/color.h
+++ b/color.h
@@ -48,6 +48,16 @@ struct strbuf;
 /* A special value meaning "no color selected" */
 #define GIT_COLOR_NIL "NIL"
 
+/*
+ * The first three are chosen to match common usage in the code, and what is
+ * returned from git_config_colorbool. The "auto" value can be returned from
+ * config_colorbool, and will be converted by want_color() into either 0 or 1.
+ */
+#define GIT_COLOR_UNKNOWN -1
+#define GIT_COLOR_NEVER  0
+#define GIT_COLOR_ALWAYS 1
+#define GIT_COLOR_AUTO   2
+
 /*
  * This variable stores the value of color.ui
  */
@@ -69,6 +79,7 @@ extern int color_stdout_is_tty;
 int git_color_default_config(const char *var, const char *value, void *cb);
 
 int git_config_colorbool(const char *var, const char *value);
+int want_color(int var);
 void color_parse(const char *value, const char *var, char *dst);
 void color_parse_mem(const char *value, int len, const char *var, char *dst);
 __attribute__((format (printf, 3, 4)))
diff --git a/diff.c b/diff.c
index 1f87f23190..0496cdc019 100644
--- a/diff.c
+++ b/diff.c
@@ -622,7 +622,7 @@ static void emit_rewrite_diff(const char *name_a,
 	size_two = fill_textconv(textconv_two, two, &data_two);
 
 	memset(&ecbdata, 0, sizeof(ecbdata));
-	ecbdata.color_diff = o->use_color > 0;
+	ecbdata.color_diff = want_color(o->use_color);
 	ecbdata.found_changesp = &o->found_changes;
 	ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 	ecbdata.opt = o;
@@ -1003,7 +1003,7 @@ static void free_diff_words_data(struct emit_callback *ecbdata)
 
 const char *diff_get_color(int diff_use_color, enum color_diff ix)
 {
-	if (diff_use_color > 0)
+	if (want_color(diff_use_color))
 		return diff_colors[ix];
 	return "";
 }
@@ -2133,7 +2133,7 @@ static void builtin_diff(const char *name_a,
 		memset(&xecfg, 0, sizeof(xecfg));
 		memset(&ecbdata, 0, sizeof(ecbdata));
 		ecbdata.label_path = lbl;
-		ecbdata.color_diff = o->use_color > 0;
+		ecbdata.color_diff = want_color(o->use_color);
 		ecbdata.found_changesp = &o->found_changes;
 		ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
 		if (ecbdata.ws_rule & WS_BLANK_AT_EOF)
@@ -2181,7 +2181,7 @@ static void builtin_diff(const char *name_a,
 					break;
 				}
 			}
-			if (o->use_color > 0) {
+			if (want_color(o->use_color)) {
 				struct diff_words_style *st = ecbdata.diff_words->style;
 				st->old.color = diff_get_color_opt(o, DIFF_FILE_OLD);
 				st->new.color = diff_get_color_opt(o, DIFF_FILE_NEW);
@@ -2831,7 +2831,7 @@ static void run_diff_cmd(const char *pgm,
 		 */
 		fill_metainfo(msg, name, other, one, two, o, p,
 			      &must_show_header,
-			      o->use_color > 0 && !pgm);
+			      want_color(o->use_color) && !pgm);
 		xfrm_msg = msg->len ? msg->buf : NULL;
 	}
 
@@ -3374,12 +3374,9 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 		options->use_color = 1;
 	else if (!prefixcmp(arg, "--color=")) {
 		int value = git_config_colorbool(NULL, arg+8);
-		if (value == 0)
-			options->use_color = 0;
-		else if (value > 0)
-			options->use_color = 1;
-		else
+		if (value < 0)
 			return error("option `color' expects \"always\", \"auto\", or \"never\"");
+		options->use_color = value;
 	}
 	else if (!strcmp(arg, "--no-color"))
 		options->use_color = 0;
diff --git a/graph.c b/graph.c
index 556834a973..7358416a72 100644
--- a/graph.c
+++ b/graph.c
@@ -347,7 +347,7 @@ static struct commit_list *first_interesting_parent(struct git_graph *graph)
 
 static unsigned short graph_get_current_column_color(const struct git_graph *graph)
 {
-	if (graph->revs->diffopt.use_color <= 0)
+	if (!want_color(graph->revs->diffopt.use_color))
 		return column_colors_max;
 	return graph->default_column_color;
 }
diff --git a/grep.c b/grep.c
index d03d9e24c2..e52654b20b 100644
--- a/grep.c
+++ b/grep.c
@@ -430,7 +430,7 @@ static int word_char(char ch)
 static void output_color(struct grep_opt *opt, const void *data, size_t size,
 			 const char *color)
 {
-	if (opt->color && color && color[0]) {
+	if (want_color(opt->color) && color && color[0]) {
 		opt->output(opt, color, strlen(color));
 		opt->output(opt, data, size);
 		opt->output(opt, GIT_COLOR_RESET, strlen(GIT_COLOR_RESET));
diff --git a/log-tree.c b/log-tree.c
index 9ba8fb2af3..95d6d4080e 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -31,7 +31,7 @@ static char decoration_colors[][COLOR_MAXLEN] = {
 
 static const char *decorate_get_color(int decorate_use_color, enum decoration_type ix)
 {
-	if (decorate_use_color > 0)
+	if (want_color(decorate_use_color))
 		return decoration_colors[ix];
 	return "";
 }
diff --git a/t/t7006-pager.sh b/t/t7006-pager.sh
index 4884e1b40c..458233693b 100755
--- a/t/t7006-pager.sh
+++ b/t/t7006-pager.sh
@@ -167,6 +167,18 @@ test_expect_success TTY 'color when writing to a pager' '
 	colorful paginated.out
 '
 
+test_expect_success TTY 'colors are suppressed by color.pager' '
+	rm -f paginated.out &&
+	test_config color.ui auto &&
+	test_config color.pager false &&
+	(
+		TERM=vt100 &&
+		export TERM &&
+		test_terminal git log
+	) &&
+	! colorful paginated.out
+'
+
 test_expect_success 'color when writing to a file intended for a pager' '
 	rm -f colorful.log &&
 	test_config color.ui auto ||
diff --git a/wt-status.c b/wt-status.c
index da4bce5816..f2016dcdcc 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -26,7 +26,9 @@ static char default_wt_status_colors[][COLOR_MAXLEN] = {
 
 static const char *color(int slot, struct wt_status *s)
 {
-	const char *c = s->use_color > 0 ? s->color_palette[slot] : "";
+	const char *c = "";
+	if (want_color(s->use_color))
+		c = s->color_palette[slot];
 	if (slot == WT_STATUS_ONBRANCH && color_is_nil(c))
 		c = s->color_palette[WT_STATUS_HEADER];
 	return c;