From an experimental study of color in conjunction with data analysis and principal component, relationships between the chromaticity coordinates
and polar components in the CIELAB space were established, finding a positive correlation in brightness and the b * parameter, representing the color change from blue to yellow, and between a* which represents green to red and their polar component, hue (h).
The fact that the stimuli appeared different in color illustrates another error in using CCT as a correlate for brightness perception: two lamps with the same CCT can have not only different chromaticity coordinates
but also a very different appearance.
10D] are chromaticity coordinates
for the 10[degrees] observer and illuminant D.
The chromaticity coordinates
of the different LEDs were a strong function of drive current, as shown in Fig.
The CIE chromaticity coordinates
can thus be thought of as the proportions of red (x), and green (y), in each colour; a third coordinate, luminance or reflectance (Y) makes up the CIE tri-stimulus values.
Proprietary Future tools were used to calculate the achievable chromaticity coordinates
and thereby determine which color bins were required to produce the required color values.
The distance between the chromaticity coordinates
of a SPD to the blackbody locus within the CIE 1960 UCS diagram is defined as Diiv, the tolerance of which is also defined by ANSI [ANSI 2008].
The CIE 1931 chromaticity coordinates
and the correlated colour temperature (CCT) were derived from the recorded spectra using spectrometer software.
This spectrometer transformed spectral data into lightness data (L) and chromaticity coordinates
(redness (a) and yellowness (b)) on the basis of a D65 light source (CIE 1986).
The calculation of complementary chromaticity coordinates
is not required for color comparisons.
The values of lightness and chromaticity coordinates
before and after weathering tests were used to calculate the discoloration ([DELTA][E.
New TAOS Digital Color Light Sensors Provide a Means for Deriving Color Temperature and Chromaticity Coordinates
to Manage LCD Display Backlighting