A color group is constructed with
ColorGroup( G, H ),
which returns a colored copy of G, with color subgroup H. G must be a parent group, and H must be a finite index subgroup of G. Color subgroups must be constructed as subgroups of color parent groups, and not by coloring uncolored subgroups. Subgroups of color groups will inherit the coloring of their parent, including the labelling of the colors.
Color groups are identified with a tag isColorGroup. They always have
a component colorSubgroup. Color parent groups moreover always have a
component colorCosets, which fixes a labelling of the colors.
Groups which may be colored include, in particular, CrystGroups, but
coloring of any finite group, such as a finite matrix group or
permutation group, should work as well.
GAP 3.4.4