image/color.CMYK.Y (field)

4 uses

	image/color (current package)
		ycbcr.go#L349: 	C, M, Y, K uint8
		ycbcr.go#L359: 	b := (0xffff - uint32(c.Y)*0x101) * w / 0xffff

	image
		image.go#L1073: 	s[2] = c1.Y
		image.go#L1098: 	s[2] = c.Y