The seed points are colored by the exteroception to interoception gradient from yellow (exteroception) to red (interoception)
See 3D view of Figure 2 from the paper.
SEE ALSO: the 109 points in MNI space, color by Network, model v. senses (gradient 2)
The identification of 109 seed points used in the paper is important, IMHO.
See Table S1 in: https://www.researchgate.net/publication/337012579_Zhang_2019_SciRep_sompdf
Check out: wikipedia/WebGL