--- ray/src/common/spec_rgb.c	2007/10/08 18:07:55	2.16
+++ ray/src/common/spec_rgb.c	2009/11/02 23:45:11	2.17
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: spec_rgb.c,v 2.16 2007/10/08 18:07:55 greg Exp $";
+static const char	RCSid[] = "$Id: spec_rgb.c,v 2.17 2009/11/02 23:45:11 greg Exp $";
 #endif
 /*
  * Convert colors and spectral ranges.
@@ -244,9 +244,11 @@ RGBPRIMS  pr
 	int	i;
 	
 	for (i = 0; i < 4; i++) {
-		if ((pr[i][CIEX] <= CEPS) | (pr[i][CIEY] <= CEPS))
+		if ((pr[i][CIEX] <= -CEPS) | (pr[i][CIEY] <= -CEPS))
 			return(0);
-		if ((pr[i][CIEX] >= 1.-CEPS) | (pr[i][CIEY] >= 1.-CEPS))
+		if ((pr[i][CIEX] >= 1.+CEPS) | (pr[i][CIEY] >= 1.+CEPS))
+			return(0);
+		if (pr[i][CIEX] + pr[i][CIEY] >= 1.+CEPS)
 			return(0);
 	}
 	return(1);