diff -ur rxvt-unicode-9.31/src/command.C rxvt-unicode-9.31_patched/src/command.C
--- rxvt-unicode-9.31/src/command.C	2022-12-23 22:36:57.000000000 +0100
+++ rxvt-unicode-9.31_patched/src/command.C	2024-05-02 12:02:47.275705061 +0200
@@ -3426,9 +3426,9 @@
         snprintf (rgba_str, sizeof (rgba_str), "rgb:%04x/%04x/%04x", c.r, c.g, c.b);
 
       if (IN_RANGE_INC (color, minCOLOR, maxTermCOLOR))
-        tt_printf ("\033]%d;%d;%s%c", report, color - minCOLOR, rgba_str, resp);
+        tt_printf ("\033]%d;%d;%s\033\\", report, color - minCOLOR, rgba_str);
       else
-        tt_printf ("\033]%d;%s%c", report, rgba_str, resp);
+        tt_printf ("\033]%d;%s\033\\", report, rgba_str, resp);
     }
   else
     set_window_color (color, str);