The CIECHROMA structure is used to describe the chromaticity coordinates, x and y, and the luminance, Y in CIE color space.
typedef struct _CIECHROMA {
LDECI4 x;
LDECI4 y;
LDECI4 Y;
} CIECHROMA;
Declared in winddi.h. Include winddi.h.
This structure is used by the COLORINFO structure to define colors for GDIINFO.
The LDECI4 type is used to represent real numbers to four decimal places. For example, (LDECI4) 10000 represents the real number 1.0000, and (LDECI4) -12345 represents -1.2345.
Both x and y should be in the range zero to one. The Y member should be in the range 0 to 100.