# https://accreditedgemologists.org/lightingtaskforce/NISTDevelopmentofColorQualityScale.pdf
# CCT factor
1000	0.32
1500	0.65
2000	0.83
2500	0.93
2856	0.97
3000	0.98
3500	1
4000	1
5000	1
6000	1
6500	1
7000	0.99
8000	0.98
9000	0.97
10000	0.96
15000	0.93
20000	0.91