diff --git a/builtin_set_color.cpp b/builtin_set_color.cpp
index 79a81bbb9..1cce8097b 100644
--- a/builtin_set_color.cpp
+++ b/builtin_set_color.cpp
@@ -211,7 +211,7 @@ static int builtin_set_color(parser_t &parser, wchar_t **argv)
     {
         if (bg.is_normal())
         {
-            write_background_color(0);
+            write_color(rgb_color_t::black(), false /* not is_fg */);
             writembs(tparm(exit_attribute_mode));
         }
     }
@@ -220,12 +220,12 @@ static int builtin_set_color(parser_t &parser, wchar_t **argv)
     {
         if (fg.is_normal() || fg.is_reset())
         {
-            write_foreground_color(0);
+            write_color(rgb_color_t::black(), true /* is_fg */);
             writembs(tparm(exit_attribute_mode));
         }
         else
         {
-            write_foreground_color(index_for_color(fg));
+            write_color(fg, true /* is_fg */);
         }
     }
 
@@ -233,7 +233,7 @@ static int builtin_set_color(parser_t &parser, wchar_t **argv)
     {
         if (! bg.is_normal() && ! bg.is_reset())
         {
-            write_background_color(index_for_color(bg));
+            write_color(bg, false /* not is_fg */);
         }
     }
 
diff --git a/color.h b/color.h
index db2fec712..b3da47d02 100644
--- a/color.h
+++ b/color.h
@@ -9,7 +9,8 @@
 #include "common.h"
 
 /* 24 bit color */
-struct color24_t {
+struct color24_t
+{
     unsigned char rgb[3];
 };
 
diff --git a/env.cpp b/env.cpp
index 6ae7f1772..2fe3767bb 100644
--- a/env.cpp
+++ b/env.cpp
@@ -323,7 +323,7 @@ static void react_to_variable_change(const wcstring &key)
     {
         handle_locale();
     }
-    else if (key == L"fish_term256")
+    else if (key == L"fish_term256" || key == L"fish_term24bit")
     {
         update_fish_color_support();
         reader_react_to_color_change();
diff --git a/input.cpp b/input.cpp
index 3b4c0ffaa..6811d0eba 100644
--- a/input.cpp
+++ b/input.cpp
@@ -465,6 +465,7 @@ void update_fish_color_support(void)
     }
     else
     {
+        /* We don't attempt to infer term24 bit support yet. */
         support_term24bit = false;
     }
 
diff --git a/output.cpp b/output.cpp
index 3a33ba7fa..312a90777 100644
--- a/output.cpp
+++ b/output.cpp
@@ -151,7 +151,7 @@ unsigned char index_for_color(rgb_color_t c)
 }
 
 
-static bool write_color(char *todo, unsigned char idx, bool is_fg)
+static bool write_color_escape(char *todo, unsigned char idx, bool is_fg)
 {
     bool result = false;
     if (idx < 16 || term256_support_is_native())
@@ -184,15 +184,15 @@ static bool write_color(char *todo, unsigned char idx, bool is_fg)
     return result;
 }
 
-bool write_foreground_color(unsigned char idx)
+static bool write_foreground_color(unsigned char idx)
 {
     if (set_a_foreground && set_a_foreground[0])
     {
-        return write_color(set_a_foreground, idx, true);
+        return write_color_escape(set_a_foreground, idx, true);
     }
     else if (set_foreground && set_foreground[0])
     {
-        return write_color(set_foreground, idx, true);
+        return write_color_escape(set_foreground, idx, true);
     }
     else
     {
@@ -200,15 +200,15 @@ bool write_foreground_color(unsigned char idx)
     }
 }
 
-bool write_background_color(unsigned char idx)
+static bool write_background_color(unsigned char idx)
 {
     if (set_a_background && set_a_background[0])
     {
-        return write_color(set_a_background, idx, false);
+        return write_color_escape(set_a_background, idx, false);
     }
     else if (set_background && set_background[0])
     {
-        return write_color(set_background, idx, false);
+        return write_color_escape(set_background, idx, false);
     }
     else
     {
@@ -216,6 +216,34 @@ bool write_background_color(unsigned char idx)
     }
 }
 
+void write_color(rgb_color_t color, bool is_fg)
+{
+    bool supports_term24bit = !! (output_get_color_support() & color_support_term24bit);
+    if (! supports_term24bit || ! color.is_rgb())
+    {
+        /* Indexed or non-24 bit color */
+        unsigned char idx = index_for_color(color);
+        (is_fg ? write_foreground_color : write_background_color)(idx);
+    }
+    else
+    {
+        /* 24 bit! No tparm here, just ANSI escape sequences.
+           Foreground: ^[38;2;<r>;<g>;<b>m
+           Background: ^[48;2;<r>;<g>;<b>m
+        */
+        color24_t rgb = color.to_color24();
+        char buff[128];
+        snprintf(buff, sizeof buff, "\x1b[%u;2;%u;%u;%um", is_fg ? 38 : 48, rgb.rgb[0], rgb.rgb[1], rgb.rgb[2]);
+        int (*writer)(char) = output_get_writer();
+        if (writer)
+        {
+            for (size_t i=0; buff[i]; i++)
+            {
+                writer(buff[i]);
+            }
+        }
+    }
+}
 
 void set_color(rgb_color_t c, rgb_color_t c2)
 {
@@ -345,7 +373,7 @@ void set_color(rgb_color_t c, rgb_color_t c2)
         }
         else if (! c.is_special())
         {
-            write_foreground_color(index_for_color(c));
+            write_color(c, true /* foreground */);
         }
     }
 
@@ -360,7 +388,7 @@ void set_color(rgb_color_t c, rgb_color_t c2)
             writembs(exit_attribute_mode);
             if (! last_color.is_normal())
             {
-                write_foreground_color(index_for_color(last_color));
+                write_color(last_color, true /* foreground */);
             }
 
 
@@ -370,7 +398,7 @@ void set_color(rgb_color_t c, rgb_color_t c2)
         }
         else if (! c2.is_special())
         {
-            write_background_color(index_for_color(c2));
+            write_color(c2, false /* not foreground */);
             last_color2 = c2;
         }
     }
diff --git a/output.h b/output.h
index 9af26f731..f0badf8a5 100644
--- a/output.h
+++ b/output.h
@@ -145,8 +145,7 @@ color_support_t output_get_color_support();
 void output_set_color_support(color_support_t support);
 
 /* Exported for builtin_set_color's usage only */
-bool write_foreground_color(unsigned char idx);
-bool write_background_color(unsigned char idx);
+void write_color(rgb_color_t color, bool is_fg);
 unsigned char index_for_color(rgb_color_t c);
 
 #endif