An RGB Solution:

In practice, the user needs to specify both the desired color and intensity. This can be done using CIE xyY values, where xy represent the CIE 1931 chromaticity coordinates, and Y represents the intensity. This approach is, however, not as intuitive as the RGB settings most lighting designers are familiar with.

Fortunately, there is a simple solution. Referring to the six-color LED module color gamut shown, we can completely enclose the six-sided color gamut in a triangle defined by the xy chromaticities of virtual red, green, and blue LEDs. It does not matter that the red LED chromaticity lies outside the horseshoe-shaped spectral locus and so represents a physically impossible color. What does matter is that the RGB values can be used to represent any color (and intensity) within the six-color LED module color gamut.

Relative spectral response: Closely matches CIE Standard Observer curves x,y,z within 6% (fi’) of the CIE
spectral luminous efficency V(lambda)
Cosine response (f2) EV: Within 3%
Receptor: Silicon photocell
Measuring function Tristimulus values: XYZ
Chromaticity: vay; Ev u’v’; Ev, Dominant wavelength, Excitation purity
Correlated color temperature: EVTCpA u’v’; TCp(JIS method; available only with CL-S10w)
Color difference: delta(XYZ), delta(vay), delta(Evu’v’), deltaEVAu’v’
Other function: User calibration function, Data hold function, Mufti-point measurement (2 to 30 points)
Measuring range: 0.1 to 99,990 lx, 0.01 to 9,999 fcd (Chromaticity: 5 lx, 0.5 fcd or above) in four
automatically selected ranges (lx or fcd is switchable)
Accuracy: EV (Linearity): i2%i1digit of displayed value xy: 3:0.002
Repeatability: Ev: 0.5%+1digit (2zetta); xy: $0.0005
Temperature drift: Ev: +/-3% zidigit of displayed value, xy: +/-0.003
Humidity drift: Ev: +/-3% i1digit of displayed value, xy: +/-0.003
Response time: 0.5 sec. (continuous measurement)
Computer interface: USB
Display: 2-significant-digit LCD with back-light illumination
Operating temperature: -10 to 40°C, relative humidity 85% or less (at 35°C) with no condensation
humidity range
Storage temperature: -20 to 55°C, relative humidity 85% or less (at 35°C) with no condensation humidity
range.