Table I
Color ranges of series of green painted samples.
Series Number of samples Dominant wavelength (mμ ) Excitation purity (%) Reflectance (%) Δ E NBS units from standard 1. Reflectance increased 16 Standard 554 33.5 28.0 — First sample W-1 554 32.1 28.5 1.1 Last sample W-14 555 31.0 33.4 6.6 2. Reflectance decreased 14 Standard 554 33.5 28.0 — First sample B-1 554 33.0 27.7 0.5 Last sample B-13 555 25.8 22.4 11.1 3. Dominant wavelength increased 17 Standard 554 32.0 29.1 — First sample Y-1 555 32.5 29.1 0.9 Last sample Y-16 562 39.0 27.9 11.6 4. Dominant wavelength decreased 16 Standard 554 31.9 28.7 — First sample Bu-1 554 31.8 28.6 0.1 Last sample Bu-15 543 23.0 23.9 9.6
Table II
Rank correlation between observed color differences and calculated color differences.
Series 1 reflectance increased set 1a Series 2 reflectance decreased set 1 Series 3 dominant wavelength increased set 1 Series 4 dominant wavelength decreased set 1 Sample number Δ E NBS units Sample number Δ E NBS units Sample number Δ E NBS units Sample number Δ E NBS units W-1 1.1 B-1 0.5 Y-1 0.9 Bu-1 0.1 W-2 1.9 B-2 1.0 Y-2 1.6 Bu-2 0.3 W-3 2.2 B-3 1.1 Y-3 2.1 Bu-3 1.3 W-4 2.8 B-4 1.2 Y-4 2.2 Bu-4 2.4 W-5 3.0 B-5 1.9 Y-5 3.0 Bu-5 2.6 W-6 3.7 B-6 2.0 Y-6 3.4 Bu-6 3.4 W-7 3.9 B-7 2.7 Y-7 4.2 Bu-7 3.6 Y-8 4.5 Rank correlation “Analyte” north daylight 1.00, 0.89, 0.96 0.82 1.00 1.00 Rank correlation north daylight 0.86, 0.92, 0.96 0.89 1.00 1.00
Series 1 reflectance increased set 2a Series 2 reflectance decreased set 2 Series 3 dominant wavelength increased set 2 Series 4 dominant wavelength decreased set 2 Sample number Δ E NBS units Sample number Δ E NBS units Sample number Δ E NBS units Sample number Δ E NBS units
W-8 4.0 B-8 5.0 Y-9 5.7 Bu-8 4.2 W-9 4.1 B-9 6.1 Y-10 6.5 Bu-9 4.6 W-10 4.5 B-10 7.4 Y-11 7.4 BU-10 5.4 W-11 4.6 B-11 8.2 Y-12 8.2 Bu-11 6.2 W-12 5.6 B-12 10.6 Y-13 9.8 Bu-12 7.2 W-13 5.8 B-13 11.1 Y-14 10.1 Bu-13 7.9 W-14 6.6 Y-15 11.1 Bu-14 8.9 Y-16 11.6 Bu-15 9.6 Rank correlation “Analyte” north daylight 0.96, 0.96, 0.96 1.00 1.00 1.00 Rank correlation north daylight 0.96, 0.99, 1.00 1.00 1.00 1.00
a Three trials made.
Table III
Colors and color differences of 9 samples selected from Series 1 to 4, inclusive, evaluated spectrophotometrically.
Chromaticity coordinates Dominant wavelength (mμ ) Excitation purity (%) Diffuse reflectance (%) Δ E NBS units Munsell renotations Sample x y H V /C Std. 0.3162 0.4280 554 31.9 27.8 — 9.5GY 5.8/6.3 B-2 0.3156 0.4269 554 31.2 27.1 0.8 9.5GY 5.7/6.3 Bu-3 0.3140 0.4234 553 30.0 27.5 1.4 9.8GY 5.8/6.2 Y-3 0.3196 0.4270 555 32.5 27.9 2.0 9.1GY 5.8/6.2 W-4 0.3162 0.4221 554 30.2 28.9 2.3 9.7GY 5.9/6.1 Bu-8 0.3091 0.4191 551 27.9 26.2 3.6 0.3G 5.7/6.0 B-8 0.3165 0.4173 554 29.0 25.5 4.5 9.8GY 5.7/5.6 W-12 0.3180 0.4215 555 30.5 32.0 4.9 9.3GY 6.2/6.2 Y-8 0.3262 0.4292 558 34.8 27.6 5.1 8.6GY 5.8/6.0
Table IV
Comparison of visual order with order of various color difference formulas.
Color difference formulas Visuala Judd Judd-Hunter-Schofield Nickerson Nickerson-Balinkin Saunderson-Milner Sample Analyte North daylight North daylight Color units Rank Color units Rank Color units Rank Color units Rank Color units Rank B-2 1 1 0.8 1 1.2 1.5 1.4 1 1.0 1 0.3 1 W-4 2 2 2.3 4 1.7 4 1.7 4 1.5 2 0.4 3 Bu-3 3 3 1.4 2 1.2 1.5 1.6 2.5 1.6 3.5 0.4 3 Y-3 4 4 2.0 3 1.5 3 1.6 2.5 1.6 3.5 0.4 3 W-12 5 5 4.9 7 3.9 7 3.2 6 2.5 5 0.7 5 B-8 6 7.5 4.5 6 4.0 8 3.4 7.5 4.6 8 1.7 8 Y-8 7 6 5.1 8 3.8 6 3.1 5 2.9 7 1.1 7 Bu-8 8 7.5 3.6 5 2.5 5 3.4 7.5 2.8 6 0.9 6 Rank correlation “Analyte” north daylight 0.76 0.70 0.83 0.89 0.82 Rank correlation north daylight 0.73 0.79 0.89 0.94 0.93
a Average order for six inexperienced observers.
Table V
Small color difference formulas.
Author Type of color space on which formula is based Judd
Δ
E
J
=
f
g
{
[
7
Y
1
4
[
(
Δ
α
)
2
+
(
Δ
β
)
2
]
1
2
10
2
]
2
+
[
k
Δ
(
Y
1
2
)
]
2
}
1
2
α
=
2.4266
x
-
1.3631
y
-
0.3214
1.0000
x
+
2.2633
y
+
1.1054
β
=
0.5710
x
+
1.2447
y
-
0.5708
1.0000
x
+
2.2633
y
+
1.1054
f
g
=
1.0
for
matte
surfaces
k
=
100 3-dimensional concept combining Judd UCS diagram with a scale of lightness
L
=
Y
1
2 . Judd-Hunter-Schofield
Δ
E
H
-
S
=
[
(
L
1
-
L
0
)
2
+
(
a
1
-
a
0
)
2
+
(
b
1
-
b
0
)
2
]
1
2
L
=
100
Y
1
2
a
=
7
L
α
b
=
7
L
β 3-dimensional concept combining Judd UCS diagram with a scale of lightness
L
=
Y
1
2 . Nickerson
I
=
C
5
(
2
Δ
H
)
+
6
Δ
V
+
3
Δ
C Munsell 3-dimensional concept of hue, value, and chroma. Nickerson-Balinkin
I
′
=
[
(
C
5
2
Δ
H
)
2
+
(
6
Δ
V
)
2
+
(
20
π
Δ
C
)
2
]
1
2 Munsell 3-dimensional concept of hue, value, and chroma. Saunderson-Milner
Δ
E
S
-
M
=
Δ
ζ
1
+
Δ
ζ
2
+
Δ
ζ
3
ζ
1
=
(
V
X
-
V
Y
)
(
9.37
+
0.79
cos
θ
)
ζ
3
=
(
V
Z
-
V
Y
)
(
3.33
+
0.87
sin
θ
)
tan
θ
=
V
X
-
V
Y
V
Z
-
V
Y
ζ
2
=
k
Δ
V
Y 3-dimensional concept in which the coordinates are ζ 1 , ζ 2 , and ζ 3 . V X , V Y , and V Z are Munsell values corresponding to X C , Y , and Z C . k may vary from 2 to 10 depending on the conditions of viewing
Table VI
Number of acceptances of sample color cards for commercial conformity.
Analyte north light Sample Average for 3 trials by 6 inexperienced observers Average for 3 trials by 4 experienced observers Natural north daylight 4 experienced observers. Resubmission W-1 6 4 4 W-2 5.7 4 4 W-3 5.7 4 4 W-5 5 3.7 2 W-7 2.7 1.7 1 W-9 2.3 2.3 0 W-11 2.3 0.7 — W-12 1.3 0 — B-1 6 4 4 B-2 5.7 4 4 B-3 5.3 3.7 4 B-4 5.7 3.7 4 B-5 5 3.3 4 B-6 4 2.3 1 B-7 1.7 2.0 1 B-8 0 0 — Y-1 6 4 4 Y-2 5.7 4 4 Y-3 4 2.3 4 Y-4 1.0 1 1 Y-5 0 0 — Y-6 0 0 — Y-7 0 0 — Y-8 0 0 — Bu-1 5.7 4 4 Bu-2 4.7 3.3 4 Bu-3 3 3.3 4 Bu-4 1.3 0.7 1 Bu-5 1.7 0.7 — Bu-6 0.3 0 — Bu-7 0.3 0 — Bu-8 0 0 —
Table VII
Specifications for colors found to be commercially acceptable matches for the standard color.
Sample Chromaticity coordinates Dominant wavelength (mμ ) Excitation purity (%) Diffuse reflectance (%) Munsell renotation Δ E NBS units x y H V /C Std. 0.3162 0.4280 554 30.9 27.8 9.5GY 5.8/6.3 — W-1 0.3159 0.4256 554 31.0 28.0 9.6GY 5.8/6.3 0.8 W-2 0.3167 0.4241 554 30.9 28.4 9.5GY 5.9/6.2 1.7 W-3 0.3167 0.4230 554 30.7 28.3 9.5GY 5.9/6.2 2.0 W-5 0.3186 0.4246 555 31.5 29.5 9.4GY 6.0/6.1 2.8 B-1 0.3164 0.4286 554 32.0 27.4 9.6GY 5.8/6.3 0.4 B-2 0.3156 0.4269 554 31.2 27.1 9.5GY 5.7/6.3 0.8 B-3 0.3155 0.4266 554 31.2 27.1 9.5GY 5.7/6.3 0.8 B-4 0.3165 0.4267 554 31.5 27.1 9.5GY 5.7/6.3 0.9 B-5 0.3167 0.4248 554 31.0 26.8 9.4GY 5.7/6.3 1.6 Y-1 0.3184 0.4276 555 32.1 28.2 9.4GY 5.8/6.2 0.9 Y-2 0.3196 0.4272 555 32.4 27.9 9.2GY 5.8/6.2 1.7 Y-3 0.3196 0.4278 555 32.5 28.0 9.1GY 5.8/6.2 2.1 Bu-1 0.3160 0.4249 554 30.8 28.1 9.7GY 5.9/6.2 1.1 Bu-2 0.3141 0.4244 553 30.1 27.7 9.8GY 5.8/6.2 1.2 Bu-3 0.3140 0.4234 553 30.0 27.5 9.8GY 5.8/6.2 1.4
Table VIII
Strictest and most liberal selections by experienced observers.a
Sample Chromaticity coordinates Dominant length (mμ ) Excitation purity (%) Diffuse reflectance (%) NBS units from standard x y W-3 0.3167 0.4230 554 30.7 28.3 2.0 W-11 0.3188 0.4228 555 31.0 31.1 4.3 B-2 0.3156 0.4269 554 31.2 27.1 0.8 B-7 0.3172 0.4234 554 30.8 26.6 2.3 Y-2 0.3196 0.4272 555 32.4 27.9 1.7 Y-4 0.3209 0.4279 556 32.9 28.0 2.6 Bu-1 0.3160 0.4249 553 30.1 27.7 1.1 Bu-5 0.3108 0.4225 551 29.6 26.8 2.5
a For any observer for trials on three different days.
Table IX
Color specifications for the green paint.
I.C.I. system Munsell renotations NBS color unit Units from standard in any color direction Chromaticity coordinates Dominant wavelengh (mμ ) Excitation purity (%) Diffuse reflectance (%) Y x y H V C Minimum 0.3140 0.4230 553 30.0 26.8 9.1GY 5.7 6.1 2.1 Standard 0.3162 0.4280 554 30.9 27.8 9.5GY 5.8 6.3 Maximum 0.3209 0.4330 555 32.5 29.5 9.8GY 6.0 6.5 Efficiency 87.8% 85.9% 85.4%