diff -up or/diffutils-2.8.1/src/side.c diffutils-2.8.1/src/side.c
--- or/diffutils-2.8.1/src/side.c	2002-02-07 19:17:04.000000000 +0100
+++ diffutils-2.8.1/src/side.c	2009-09-17 10:17:36.000000000 +0200
@@ -60,6 +60,31 @@ tab_from_to (unsigned int from, unsigned
   return to;
 }
 
+
+static int
+is_ctrl(char c, const char* cc)
+{
+#if 0
+    static int in_ctrl=0;
+    if (c==27)
+    {
+        in_ctrl=1;
+    }
+    else if (c=='m')
+    {
+        in_ctrl=0;
+        return 1;
+    }
+    return in_ctrl;
+#else
+    return ( ( (c=='[')   && ((*(cc-1)==27)) ) ||
+             ( isdigit(c) && ((*(cc-2)==27) ||
+                              (*(cc-3)==27)) ) ||
+             ( (c=='m')   && ((*(cc-3)==27) ||
+                              (*(cc-4)==27)) ) );
+#endif
+}
+
 /*
  * Print the text for half an sdiff line.  This means truncate to width
  * observing tabs, and trim a trailing newline.  Returns the last column
@@ -136,7 +161,7 @@ print_half_line (char const *const *line
 	  break;
 
 	default:
-	  if (! ISPRINT (c))
+	  if ( is_ctrl (c,text_pointer-1) || (! ISPRINT (c)) )
 	    goto control_char;
 	  /* falls through */
 	case ' ':