diff --git a/doc/fixes37.0 b/doc/fixes37.0
index a96f261e5..2921d7b88 100644
--- a/doc/fixes37.0
+++ b/doc/fixes37.0
@@ -1,4 +1,4 @@
-$NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.17 $ $NHDT-Date: 1575542023 2019/12/05 10:33:43 $
+$NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.19 $ $NHDT-Date: 1575755075 2019/12/07 21:44:35 $
 
 General Fixes and Modified Features
 -----------------------------------
@@ -40,6 +40,7 @@ split off some of the functionality that was in makedefs (compiled-in options
 	and accessed on the target platform
 replace quest.txt and associated conversion to quest.dat via makedefs with
 	lua quest texts loaded at runtime
+some altars are displayed in different colors (for tty and curses at least)
 
 
 Platform- and/or Interface-Specific New Features
diff --git a/src/mapglyph.c b/src/mapglyph.c
index 082186df6..bc7e4f727 100644
--- a/src/mapglyph.c
+++ b/src/mapglyph.c
@@ -1,4 +1,4 @@
-/* NetHack 3.6	mapglyph.c	$NHDT-Date: 1573943501 2019/11/16 22:31:41 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.51 $ */
+/* NetHack 3.6	mapglyph.c	$NHDT-Date: 1575755075 2019/12/07 21:44:35 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.58 $ */
 /* Copyright (c) David Cohrs, 1991                                */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -138,8 +138,52 @@ unsigned mgflags;
            if they use the same symbol and color is disabled */
         } else if (!iflags.use_color && offset == S_lava
                    && (g.showsyms[idx] == g.showsyms[S_pool + SYM_OFF_P]
-                       || g.showsyms[idx] == g.showsyms[S_water + SYM_OFF_P])) {
+                       || g.showsyms[idx]
+                          == g.showsyms[S_water + SYM_OFF_P])) {
             special |= MG_BW_LAVA;
+        } else if (offset == S_altar && iflags.use_color) {
+            if ((Is_astralevel(&u.uz) || Is_sanctum(&u.uz))
+                && (levl[x][y].altarmask & AM_SHRINE)) {
+                /* high altar */
+                color = CLR_BRIGHT_MAGENTA;
+            } else {
+                switch (levl[x][y].altarmask & AM_MASK) {
+#if 0   /*
+         * On OSX with XTERM=xterm-color256 these render as
+         *  white -> tty: gray, curses: ok
+         *  gray  -> both tty and curses: black
+         *  black -> both tty and curses: blue
+         *  red   -> both tty and curses: ok.
+         * Since the colors have specific associations (mainly with
+         * the unicorns matched with each alignment), we shouldn't use
+         * scrambled colors and we don't have sufficient information
+         * to handle platform-specific variations.
+         */
+                case AM_LAWFUL:  /* 4 */
+                    color = CLR_WHITE;
+                    break;
+                case AM_NEUTRAL: /* 2 */
+                    color = CLR_GRAY;
+                    break;
+                case AM_CHAOTIC: /* 1 */
+                    color = CLR_BLACK;
+                    break;
+#else /* !0: TEMP? */
+                case AM_LAWFUL:  /* 4 */
+                case AM_NEUTRAL: /* 2 */
+                case AM_CHAOTIC: /* 1 */
+                    cmap_color(S_altar); /* gray */
+                    break;
+#endif /* 0 */
+                case AM_NONE:    /* 0 */
+                    color = CLR_RED;
+                    break;
+                default: /* 3, 5..7 -- shouldn't happen but 3 was possible
+                          * prior to 3.6.3 (due to faulty sink polymorph) */
+                    color = NO_COLOR;
+                    break;
+                }
+            }
         } else {
             cmap_color(offset);
         }
diff --git a/src/pray.c b/src/pray.c
index a2f667a29..0da0c2a23 100644
--- a/src/pray.c
+++ b/src/pray.c
@@ -1,4 +1,4 @@
-/* NetHack 3.6	pray.c	$NHDT-Date: 1573346192 2019/11/10 00:36:32 $  $NHDT-Branch: NetHack-3.6 $:$NHDT-Revision: 1.118 $ */
+/* NetHack 3.6	pray.c	$NHDT-Date: 1575755077 2019/12/07 21:44:37 $  $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.133 $ */
 /* Copyright (c) Benson I. Margulies, Mike Stephenson, Steve Linhart, 1989. */
 /* NetHack may be freely redistributed.  See license for details. */
 
@@ -1384,6 +1384,7 @@ dosacrifice()
                 /* curse the lawful/neutral altar */
                 pline_The("altar is stained with %s blood.", g.urace.adj);
                 levl[u.ux][u.uy].altarmask = AM_CHAOTIC;
+                newsym(u.ux, u.uy); /* in case Invisible to self */
                 angry_priest();
             } else {
                 struct monst *dmon;
@@ -1640,15 +1641,16 @@ dosacrifice()
                     a_gname());
                 if (rn2(8 + u.ulevel) > 5) {
                     struct monst *pri;
+                    boolean shrine;
+
                     You_feel("the power of %s increase.", u_gname());
                     exercise(A_WIS, TRUE);
                     change_luck(1);
-                    /* Yes, this is supposed to be &=, not |= */
-                    levl[u.ux][u.uy].altarmask &= AM_SHRINE;
-                    /* the following accommodates stupid compilers */
-                    levl[u.ux][u.uy].altarmask =
-                        levl[u.ux][u.uy].altarmask
-                        | (Align2amask(u.ualign.type));
+                    shrine = on_shrine();
+                    levl[u.ux][u.uy].altarmask = Align2amask(u.ualign.type);
+                    if (shrine)
+                        levl[u.ux][u.uy].altarmask |= AM_SHRINE;
+                    newsym(u.ux, u.uy); /* in case Invisible to self */
                     if (!Blind)
                         pline_The("altar glows %s.",
                                   hcolor((u.ualign.type == A_LAWFUL)