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Virtual Atlas - Extended
This option includes or excludes additional colour samples displayed for the selected atlas screen. The origin and composition of these additional samples varies between the systems and also between differently sourced data sets (e.g. aim and actual data sets). Systems and data sets that support additional samples together with the origin of the extended sample points is detailed below.

DIN 6164: C/1931 Aim, D65/1931 Aim, and D65/1964 Aim
Incorporates additional saturated colours beyond those presented in the DIN-6164 colour atlas.
Munsell: C/1931 Aim
Newhall, Nickerson, and Judd's (1943) final report on the spacing of the Munsell colors extended the system to include aim points for highly saturated colours.
NCS: All sample sets including user supplied data sets
Applies an extrapolation algorithm to the set of samples on a hue to calculate the missing colours in 10 unit steps along the chromaticness and blackness axes.
OSA-UCS: D65/1964 Aim
Incorporates additional saturated colours beyond those presented in the OSA-UCS colour atlas.
SCA-2541: All sample sets including user supplied data sets
Applies an extrapolation algorithm to the set of samples on a hue to calculate the missing colours in unit steps along the chroma and whiteness axes.

The two screenshots below display Munsell Hue 2.5YR with the extended samples disabled and enabled, respectively:

Extended samples disabled
Extended samples enabled
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