A method for making an illumination apparatus comprising a composite light source, which comprises at least one blue light source having a peak wavelength in the range of about 400 nanometer (nm) to about 460 nm; at least one green or yellow-green light source having a peak wavelength in the range of about 500 nm to about 580 nm; and at least one red light source having peak wavelength in the range of about 600 nm to about 680 nm; characterized in that the composite light source has a Lighting Preference Index of at least 120, wherein the LPI is defined as follows: LPI = 100 + 19 × 1 − 100 Duv + 0.010 2 + 0.62 × NSV − HDV / 2.5 where Duv is a distance of a color point from Planckian locus in u-v space, NSV is Net Saturation Value of an illumination source, wherein NSV is defined by the equation NSV i = percent of CRVs in hue i with 2.3 < ΔC ab < 15) - (percent of CRVs in hue i with ΔC ab < - 2.3), and the equation NSV = ∑ 10 i = 1 NSV i / 10, and HDV is Hue Distortion Value, wherein HDV is defined by the equation HDV i = (percent of CRVs in hue i with Δ h ab > π 20) × Δ hab,avg,i π / 20, and the equation HDV = ∑ 10 i = 1 ​ HDVi/10 furthermore the method comprising the following steps: (a) Providing the spectrum of the light emitted by the test illuminant as its Spectral Power Distribution having 1-2 nm, (or finer), precision; (b) Determining the color point (color temperature and Duv) from the SPD of the test illuminant; (c) Calculating the Whiteness component from Duv using Equation; (c') Determining the reference spectrum from the color temperature of the test illuminant; (d') Calculating the color points of all 1600 Munsell colors in the CIELAB color space for both the reference and test illuminants; (e') Calculating the color rendition vectors for the test illuminant, relative to the reference spectrum; (f) Calculating the Net Saturation Value and the Hue Distortion Value using Equation and Equation, respectively; (g') Calculating the Color Appearance component using Equation; and (d) Merging the Whiteness component from step (c) and the Color Appearance component from step (g') into the LPI using Equation. at least one blue light source having a peak wavelength in the range of about 400 nanometer (nm) to about 460 nm; at least one green or yellow-green light source having a peak wavelength in the range of about 500 nm to about 580 nm; and at least one red light source having peak wavelength in the range of about 600 nm to about 680 nm; characterized in that the composite light source has a Lighting Preference Index of at least 120, wherein the LPI is defined as follows: LPI = 100 + 19 × 1 − 100 Duv + 0.010 2 + 0.62 × NSV − HDV / 2.5 where Duv is a distance of a color point from Planckian locus in u-v space, NSV is Net Saturation Value of an illumination source, wherein NSV is defined by the equation NSV i = percent of CRVs in hue i with 2.3 < ΔC ab < 15) - (percent of CRVs in hue i with ΔC ab < - 2.3), and the equation NSV = ∑ 10 i = 1 NSV i / 10, and HDV is Hue Distortion Value, wherein HDV is defined by the equation HDV i = (percent of CRVs in hue i with Δ h ab > π 20) × Δ hab,avg,i π / 20, and the equation HDV = ∑ 10 i = 1 ​ HDVi/10 furthermore the method comprising the following steps: (a) Providing the spectrum of the light emitted by the test illuminant as its Spectral Power Distribution having 1-2 nm, (or finer), precision; (b) Determining the color point (color temperature and Duv) from the SPD of the test illuminant; (c) Calculating the Whiteness component from Duv using Equation; (c') Determining the reference spectrum from the color temperature of the test illuminant; (d') Calculating the color points of all 1600 Munsell colors in the CIELAB color space for both the reference and test illuminants; (e') Calculating the color rendition vectors for the test illuminant, relative to the reference spectrum; (f) Calculating the Net Saturation Value and the Hue Distortion Value using Equation and Equation, respectively; (g') Calculating the Color Appearance component using Equation; and (d) Merging the Whiteness component from step (c) and the Color Appearance component from step (g') into the LPI using Equation. (a) Providing the spectrum of the light emitted by the test illuminant as its Spectral Power Distribution having 1-2 nm, (or finer), precision; (b) Determining the color point (color temperature and Duv) from the SPD of the test illuminant; (c) Calculating the Whiteness component from Duv using Equation; (c') Determining the reference spectrum from the color temperature of the test illuminant; (d') Calculating the color points of all 1600 Munsell colors in the CIELAB color space for both the reference and test illuminants; (e') Calculating the color rendition vectors for the test illuminant, relative to the reference spectrum; (f) Calculating the Net Saturation Value and the Hue Distortion Value using Equation and Equation, respectively; (g') Calculating the Color Appearance component using Equation; and (d) Merging the Whiteness component from step (c) and the Color Appearance component from step (g') into the LPI using Equation.