--- ray/src/common/ccolor.h	2012/05/18 20:43:13	3.5
+++ ray/src/common/ccolor.h	2012/06/26 17:59:16	3.6
@@ -1,4 +1,4 @@
-/* RCSid $Id: ccolor.h,v 3.5 2012/05/18 20:43:13 greg Exp $ */
+/* RCSid $Id: ccolor.h,v 3.6 2012/06/26 17:59:16 greg Exp $ */
 /*
  *  Header file for spectral colors.
  *
@@ -46,7 +46,9 @@ typedef struct {
 #define c_cval(c,l)	((c)->ssamp[((l)+(C_CWLI/2.-C_MINWL))/C_CWLI] \
 						/ (double)(c)->ssum)
 
-extern C_COLOR		c_dfcolor;		/* default color */
+extern const C_COLOR	c_dfcolor;		/* default color */
+
+extern const C_COLOR	c_x31, c_y31, c_z31;	/* 1931 standard observer */
 
 						/* set CIE (x,y) chromaticity */
 #define c_cset(c,x,y)	((c)->cx=(x),(c)->cy=(y),(c)->flags=C_CDXY|C_CSXY)