The de Grey-Haugstrup graphs are two 6-chromatic graphs on 47 and 48 vertices that are unit-distance in 3 dimensions (de Grey and Haugstrup 2020).
The 47-de Grey-Haugstrup graph was also used by Haugstrup (2026) in the construction of a the 21217-vertex Haugstrup graph.
The de Grey-Haugstrup graph on 47 vertices is implemented in the Wolfram Language as GraphData["DeGreyHaugstrupGraph47"].