Specify scheme to color the atoms by. Default is
"default". Other choies are "Carbon", ssPyMOL", "ssJmol", "Jmol",
"default", "amino",
"shapely", "nucleic", "chain", "chainHetatm", "prop".
color
Discrete, fixed coloring, overrides any colorScheme.
radius
Override van der waals radius.
hidden
Boolean - do not show atom. Default FALSE.
opacity
Opacity of spheres, 0 being invisible. Must be the same for
all atoms in the model.